xref: /linux/drivers/gpu/drm/drm_syncobj.c (revision fcab107abe1ab5be9dbe874baa722372da8f4f73)
1 /*
2  * Copyright 2017 Red Hat
3  * Parts ported from amdgpu (fence wait code).
4  * Copyright 2016 Advanced Micro Devices, Inc.
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a
7  * copy of this software and associated documentation files (the "Software"),
8  * to deal in the Software without restriction, including without limitation
9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
10  * and/or sell copies of the Software, and to permit persons to whom the
11  * Software is furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice (including the next
14  * paragraph) shall be included in all copies or substantial portions of the
15  * Software.
16  *
17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
20  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
22  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
23  * IN THE SOFTWARE.
24  *
25  * Authors:
26  *
27  */
28 
29 /**
30  * DOC: Overview
31  *
32  * DRM synchronisation objects (syncobj, see struct &drm_syncobj) provide a
33  * container for a synchronization primitive which can be used by userspace
34  * to explicitly synchronize GPU commands, can be shared between userspace
35  * processes, and can be shared between different DRM drivers.
36  * Their primary use-case is to implement Vulkan fences and semaphores.
37  * The syncobj userspace API provides ioctls for several operations:
38  *
39  *  - Creation and destruction of syncobjs
40  *  - Import and export of syncobjs to/from a syncobj file descriptor
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
45  *
46  * The syncobj userspace API also provides operations to manipulate a syncobj
47  * in terms of a timeline of struct &dma_fence_chain rather than a single
48  * struct &dma_fence, through the following operations:
49  *
50  *   - Signal a given point on the timeline
51  *   - Wait for a given point to appear and/or be signaled
52  *   - Import and export from/to a given point of a timeline
53  *
54  * At it's core, a syncobj is simply a wrapper around a pointer to a struct
55  * &dma_fence which may be NULL.
56  * When a syncobj is first created, its pointer is either NULL or a pointer
57  * to an already signaled fence depending on whether the
58  * &DRM_SYNCOBJ_CREATE_SIGNALED flag is passed to
59  * &DRM_IOCTL_SYNCOBJ_CREATE.
60  *
61  * If the syncobj is considered as a binary (its state is either signaled or
62  * unsignaled) primitive, when GPU work is enqueued in a DRM driver to signal
63  * the syncobj, the syncobj's fence is replaced with a fence which will be
64  * signaled by the completion of that work.
65  * If the syncobj is considered as a timeline primitive, when GPU work is
66  * enqueued in a DRM driver to signal the a given point of the syncobj, a new
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
70  * completion of the DRM driver's work and also any work associated with the
71  * fence previously in the syncobj.
72  *
73  * When GPU work which waits on a syncobj is enqueued in a DRM driver, at the
74  * time the work is enqueued, it waits on the syncobj's fence before
75  * submitting the work to hardware. That fence is either :
76  *
77  *    - The syncobj's current fence if the syncobj is considered as a binary
78  *      primitive.
79  *    - The struct &dma_fence associated with a given point if the syncobj is
80  *      considered as a timeline primitive.
81  *
82  * If the syncobj's fence is NULL or not present in the syncobj's timeline,
83  * the enqueue operation is expected to fail.
84  *
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
87  * regardless of whether that operation is an immediate host-side operation
88  * (signal or reset) or or an operation which is enqueued in some driver
89  * queue. &DRM_IOCTL_SYNCOBJ_RESET and &DRM_IOCTL_SYNCOBJ_SIGNAL can be used
90  * to manipulate a syncobj from the host by resetting its pointer to NULL or
91  * setting its pointer to a fence which is already signaled.
92  *
93  * With a timeline syncobj, all manipulation of the synobj's fence happens in
94  * terms of a u64 value referring to point in the timeline. See
95  * dma_fence_chain_find_seqno() to see how a given point is found in the
96  * timeline.
97  *
98  * Note that applications should be careful to always use timeline set of
99  * ioctl() when dealing with syncobj considered as timeline. Using a binary
100  * set of ioctl() with a syncobj considered as timeline could result incorrect
101  * synchronization. The use of binary syncobj is supported through the
102  * timeline set of ioctl() by using a point value of 0, this will reproduce
103  * the behavior of the binary set of ioctl() (for example replace the
104  * syncobj's fence when signaling).
105  *
106  *
107  * Host-side wait on syncobjs
108  * --------------------------
109  *
110  * &DRM_IOCTL_SYNCOBJ_WAIT takes an array of syncobj handles and does a
111  * host-side wait on all of the syncobj fences simultaneously.
112  * If &DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL is set, the wait ioctl will wait on
113  * all of the syncobj fences to be signaled before it returns.
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.
116  *
117  * Unlike the enqueued GPU work dependencies which fail if they see a NULL
118  * fence in a syncobj, if &DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT is set,
119  * the host-side wait will first wait for the syncobj to receive a non-NULL
120  * fence and then wait on that fence.
121  * If &DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT is not set and any one of the
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
124  * to do a host wait in one thread (or process) which waits on GPU work
125  * submitted in another thread (or process) without having to manually
126  * synchronize between the two.
127  * This requirement is inherited from the Vulkan fence API.
128  *
129  * If &DRM_SYNCOBJ_WAIT_FLAGS_WAIT_DEADLINE is set, the ioctl will also set
130  * a fence deadline hint on the backing fences before waiting, to provide the
131  * fence signaler with an appropriate sense of urgency.  The deadline is
132  * specified as an absolute &CLOCK_MONOTONIC value in units of ns.
133  *
134  * Similarly, &DRM_IOCTL_SYNCOBJ_TIMELINE_WAIT takes an array of syncobj
135  * handles as well as an array of u64 points and does a host-side wait on all
136  * of syncobj fences at the given points simultaneously.
137  *
138  * &DRM_IOCTL_SYNCOBJ_TIMELINE_WAIT also adds the ability to wait for a given
139  * fence to materialize on the timeline without waiting for the fence to be
140  * signaled by using the &DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE flag. This
141  * requirement is inherited from the wait-before-signal behavior required by
142  * the Vulkan timeline semaphore API.
143  *
144  * Alternatively, &DRM_IOCTL_SYNCOBJ_EVENTFD can be used to wait without
145  * blocking: an eventfd will be signaled when the syncobj is. This is useful to
146  * integrate the wait in an event loop.
147  *
148  *
149  * Import/export of syncobjs
150  * -------------------------
151  *
152  * &DRM_IOCTL_SYNCOBJ_FD_TO_HANDLE and &DRM_IOCTL_SYNCOBJ_HANDLE_TO_FD
153  * provide two mechanisms for import/export of syncobjs.
154  *
155  * The first lets the client import or export an entire syncobj to a file
156  * descriptor.
157  * These fd's are opaque and have no other use case, except passing the
158  * syncobj between processes.
159  * All exported file descriptors and any syncobj handles created as a
160  * result of importing those file descriptors own a reference to the
161  * same underlying struct &drm_syncobj and the syncobj can be used
162  * persistently across all the processes with which it is shared.
163  * The syncobj is freed only once the last reference is dropped.
164  * Unlike dma-buf, importing a syncobj creates a new handle (with its own
165  * reference) for every import instead of de-duplicating.
166  * The primary use-case of this persistent import/export is for shared
167  * Vulkan fences and semaphores.
168  *
169  * The second import/export mechanism, which is indicated by
170  * &DRM_SYNCOBJ_FD_TO_HANDLE_FLAGS_IMPORT_SYNC_FILE or
171  * &DRM_SYNCOBJ_HANDLE_TO_FD_FLAGS_EXPORT_SYNC_FILE lets the client
172  * import/export the syncobj's current fence from/to a &sync_file.
173  * When a syncobj is exported to a sync file, that sync file wraps the
174  * sycnobj's fence at the time of export and any later signal or reset
175  * operations on the syncobj will not affect the exported sync file.
176  * When a sync file is imported into a syncobj, the syncobj's fence is set
177  * to the fence wrapped by that sync file.
178  * Because sync files are immutable, resetting or signaling the syncobj
179  * will not affect any sync files whose fences have been imported into the
180  * syncobj.
181  *
182  *
183  * Import/export of timeline points in timeline syncobjs
184  * -----------------------------------------------------
185  *
186  * &DRM_IOCTL_SYNCOBJ_TRANSFER provides a mechanism to transfer a struct
187  * &dma_fence_chain of a syncobj at a given u64 point to another u64 point
188  * into another syncobj.
189  *
190  * Note that if you want to transfer a struct &dma_fence_chain from a given
191  * point on a timeline syncobj from/into a binary syncobj, you can use the
192  * point 0 to mean take/replace the fence in the syncobj.
193  */
194 
195 #include <linux/anon_inodes.h>
196 #include <linux/dma-fence-unwrap.h>
197 #include <linux/eventfd.h>
198 #include <linux/file.h>
199 #include <linux/fs.h>
200 #include <linux/sched/signal.h>
201 #include <linux/sync_file.h>
202 #include <linux/uaccess.h>
203 
204 #include <drm/drm.h>
205 #include <drm/drm_drv.h>
206 #include <drm/drm_file.h>
207 #include <drm/drm_gem.h>
208 #include <drm/drm_print.h>
209 #include <drm/drm_syncobj.h>
210 #include <drm/drm_utils.h>
211 
212 #include "drm_internal.h"
213 
214 struct syncobj_wait_entry {
215 	struct list_head node;
216 	struct task_struct *task;
217 	struct dma_fence *fence;
218 	struct dma_fence_cb fence_cb;
219 	u64    point;
220 };
221 
222 static void syncobj_wait_syncobj_func(struct drm_syncobj *syncobj,
223 				      struct syncobj_wait_entry *wait);
224 
225 struct syncobj_eventfd_entry {
226 	struct list_head node;
227 	struct dma_fence *fence;
228 	struct dma_fence_cb fence_cb;
229 	struct drm_syncobj *syncobj;
230 	struct eventfd_ctx *ev_fd_ctx;
231 	u64 point;
232 	u32 flags;
233 };
234 
235 static void
236 syncobj_eventfd_entry_func(struct drm_syncobj *syncobj,
237 			   struct syncobj_eventfd_entry *entry);
238 
239 /**
240  * drm_syncobj_find - lookup and reference a sync object.
241  * @file_private: drm file private pointer
242  * @handle: sync object handle to lookup.
243  *
244  * Returns a reference to the syncobj pointed to by handle or NULL. The
245  * reference must be released by calling drm_syncobj_put().
246  */
247 struct drm_syncobj *drm_syncobj_find(struct drm_file *file_private,
248 				     u32 handle)
249 {
250 	struct drm_syncobj *syncobj;
251 
252 	spin_lock(&file_private->syncobj_table_lock);
253 
254 	/* Check if we currently have a reference on the object */
255 	syncobj = idr_find(&file_private->syncobj_idr, handle);
256 	if (syncobj)
257 		drm_syncobj_get(syncobj);
258 
259 	spin_unlock(&file_private->syncobj_table_lock);
260 
261 	return syncobj;
262 }
263 EXPORT_SYMBOL(drm_syncobj_find);
264 
265 static void drm_syncobj_fence_add_wait(struct drm_syncobj *syncobj,
266 				       struct syncobj_wait_entry *wait)
267 {
268 	struct dma_fence *fence;
269 
270 	if (wait->fence)
271 		return;
272 
273 	spin_lock(&syncobj->lock);
274 	/* We've already tried once to get a fence and failed.  Now that we
275 	 * have the lock, try one more time just to be sure we don't add a
276 	 * callback when a fence has already been set.
277 	 */
278 	fence = dma_fence_get(rcu_dereference_protected(syncobj->fence, 1));
279 	if (!fence || dma_fence_chain_find_seqno(&fence, wait->point)) {
280 		dma_fence_put(fence);
281 		list_add_tail(&wait->node, &syncobj->cb_list);
282 	} else if (!fence) {
283 		wait->fence = dma_fence_get_stub();
284 	} else {
285 		wait->fence = fence;
286 	}
287 	spin_unlock(&syncobj->lock);
288 }
289 
290 static void drm_syncobj_remove_wait(struct drm_syncobj *syncobj,
291 				    struct syncobj_wait_entry *wait)
292 {
293 	if (!wait->node.next)
294 		return;
295 
296 	spin_lock(&syncobj->lock);
297 	list_del_init(&wait->node);
298 	spin_unlock(&syncobj->lock);
299 }
300 
301 static void
302 syncobj_eventfd_entry_free(struct syncobj_eventfd_entry *entry)
303 {
304 	eventfd_ctx_put(entry->ev_fd_ctx);
305 	dma_fence_put(entry->fence);
306 	/* This happens either inside the syncobj lock, or after the node has
307 	 * already been removed from the list.
308 	 */
309 	list_del(&entry->node);
310 	kfree(entry);
311 }
312 
313 static void
314 drm_syncobj_add_eventfd(struct drm_syncobj *syncobj,
315 			struct syncobj_eventfd_entry *entry)
316 {
317 	spin_lock(&syncobj->lock);
318 	list_add_tail(&entry->node, &syncobj->ev_fd_list);
319 	syncobj_eventfd_entry_func(syncobj, entry);
320 	spin_unlock(&syncobj->lock);
321 }
322 
323 /**
324  * drm_syncobj_add_point - add new timeline point to the syncobj
325  * @syncobj: sync object to add timeline point do
326  * @chain: chain node to use to add the point
327  * @fence: fence to encapsulate in the chain node
328  * @point: sequence number to use for the point
329  *
330  * Add the chain node as new timeline point to the syncobj.
331  */
332 void drm_syncobj_add_point(struct drm_syncobj *syncobj,
333 			   struct dma_fence_chain *chain,
334 			   struct dma_fence *fence,
335 			   uint64_t point)
336 {
337 	struct syncobj_wait_entry *wait_cur, *wait_tmp;
338 	struct syncobj_eventfd_entry *ev_fd_cur, *ev_fd_tmp;
339 	struct dma_fence *prev;
340 
341 	dma_fence_get(fence);
342 
343 	spin_lock(&syncobj->lock);
344 
345 	prev = drm_syncobj_fence_get(syncobj);
346 	/* You are adding an unorder point to timeline, which could cause payload returned from query_ioctl is 0! */
347 	if (prev && prev->seqno >= point)
348 		DRM_DEBUG("You are adding an unorder point to timeline!\n");
349 	dma_fence_chain_init(chain, prev, fence, point);
350 	rcu_assign_pointer(syncobj->fence, &chain->base);
351 
352 	list_for_each_entry_safe(wait_cur, wait_tmp, &syncobj->cb_list, node)
353 		syncobj_wait_syncobj_func(syncobj, wait_cur);
354 	list_for_each_entry_safe(ev_fd_cur, ev_fd_tmp, &syncobj->ev_fd_list, node)
355 		syncobj_eventfd_entry_func(syncobj, ev_fd_cur);
356 	spin_unlock(&syncobj->lock);
357 
358 	/* Walk the chain once to trigger garbage collection */
359 	dma_fence_chain_for_each(fence, prev);
360 	dma_fence_put(prev);
361 }
362 EXPORT_SYMBOL(drm_syncobj_add_point);
363 
364 /**
365  * drm_syncobj_replace_fence - replace fence in a sync object.
366  * @syncobj: Sync object to replace fence in
367  * @fence: fence to install in sync file.
368  *
369  * This replaces the fence on a sync object.
370  */
371 void drm_syncobj_replace_fence(struct drm_syncobj *syncobj,
372 			       struct dma_fence *fence)
373 {
374 	struct dma_fence *old_fence;
375 	struct syncobj_wait_entry *wait_cur, *wait_tmp;
376 	struct syncobj_eventfd_entry *ev_fd_cur, *ev_fd_tmp;
377 
378 	if (fence)
379 		dma_fence_get(fence);
380 
381 	spin_lock(&syncobj->lock);
382 
383 	old_fence = rcu_dereference_protected(syncobj->fence,
384 					      lockdep_is_held(&syncobj->lock));
385 	rcu_assign_pointer(syncobj->fence, fence);
386 
387 	if (fence != old_fence) {
388 		list_for_each_entry_safe(wait_cur, wait_tmp, &syncobj->cb_list, node)
389 			syncobj_wait_syncobj_func(syncobj, wait_cur);
390 		list_for_each_entry_safe(ev_fd_cur, ev_fd_tmp, &syncobj->ev_fd_list, node)
391 			syncobj_eventfd_entry_func(syncobj, ev_fd_cur);
392 	}
393 
394 	spin_unlock(&syncobj->lock);
395 
396 	dma_fence_put(old_fence);
397 }
398 EXPORT_SYMBOL(drm_syncobj_replace_fence);
399 
400 /**
401  * drm_syncobj_assign_null_handle - assign a stub fence to the sync object
402  * @syncobj: sync object to assign the fence on
403  *
404  * Assign a already signaled stub fence to the sync object.
405  */
406 static int drm_syncobj_assign_null_handle(struct drm_syncobj *syncobj)
407 {
408 	struct dma_fence *fence = dma_fence_allocate_private_stub(ktime_get());
409 
410 	if (!fence)
411 		return -ENOMEM;
412 
413 	drm_syncobj_replace_fence(syncobj, fence);
414 	dma_fence_put(fence);
415 	return 0;
416 }
417 
418 /* 5s default for wait submission */
419 #define DRM_SYNCOBJ_WAIT_FOR_SUBMIT_TIMEOUT 5000000000ULL
420 /**
421  * drm_syncobj_find_fence - lookup and reference the fence in a sync object
422  * @file_private: drm file private pointer
423  * @handle: sync object handle to lookup.
424  * @point: timeline point
425  * @flags: DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT or not
426  * @fence: out parameter for the fence
427  *
428  * This is just a convenience function that combines drm_syncobj_find() and
429  * drm_syncobj_fence_get().
430  *
431  * Returns 0 on success or a negative error value on failure. On success @fence
432  * contains a reference to the fence, which must be released by calling
433  * dma_fence_put().
434  */
435 int drm_syncobj_find_fence(struct drm_file *file_private,
436 			   u32 handle, u64 point, u64 flags,
437 			   struct dma_fence **fence)
438 {
439 	struct drm_syncobj *syncobj = drm_syncobj_find(file_private, handle);
440 	struct syncobj_wait_entry wait;
441 	u64 timeout = nsecs_to_jiffies64(DRM_SYNCOBJ_WAIT_FOR_SUBMIT_TIMEOUT);
442 	int ret;
443 
444 	if (flags & ~DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT)
445 		return -EINVAL;
446 
447 	if (!syncobj)
448 		return -ENOENT;
449 
450 	/* Waiting for userspace with locks help is illegal cause that can
451 	 * trivial deadlock with page faults for example. Make lockdep complain
452 	 * about it early on.
453 	 */
454 	if (flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT) {
455 		might_sleep();
456 		lockdep_assert_none_held_once();
457 	}
458 
459 	*fence = drm_syncobj_fence_get(syncobj);
460 
461 	if (*fence) {
462 		ret = dma_fence_chain_find_seqno(fence, point);
463 		if (!ret) {
464 			/* If the requested seqno is already signaled
465 			 * drm_syncobj_find_fence may return a NULL
466 			 * fence. To make sure the recipient gets
467 			 * signalled, use a new fence instead.
468 			 */
469 			if (!*fence)
470 				*fence = dma_fence_get_stub();
471 
472 			goto out;
473 		}
474 		dma_fence_put(*fence);
475 	} else {
476 		ret = -EINVAL;
477 	}
478 
479 	if (!(flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT))
480 		goto out;
481 
482 	memset(&wait, 0, sizeof(wait));
483 	wait.task = current;
484 	wait.point = point;
485 	drm_syncobj_fence_add_wait(syncobj, &wait);
486 
487 	do {
488 		set_current_state(TASK_INTERRUPTIBLE);
489 		if (wait.fence) {
490 			ret = 0;
491 			break;
492 		}
493                 if (timeout == 0) {
494                         ret = -ETIME;
495                         break;
496                 }
497 
498 		if (signal_pending(current)) {
499 			ret = -ERESTARTSYS;
500 			break;
501 		}
502 
503                 timeout = schedule_timeout(timeout);
504 	} while (1);
505 
506 	__set_current_state(TASK_RUNNING);
507 	*fence = wait.fence;
508 
509 	if (wait.node.next)
510 		drm_syncobj_remove_wait(syncobj, &wait);
511 
512 out:
513 	drm_syncobj_put(syncobj);
514 
515 	return ret;
516 }
517 EXPORT_SYMBOL(drm_syncobj_find_fence);
518 
519 /**
520  * drm_syncobj_free - free a sync object.
521  * @kref: kref to free.
522  *
523  * Only to be called from kref_put in drm_syncobj_put.
524  */
525 void drm_syncobj_free(struct kref *kref)
526 {
527 	struct drm_syncobj *syncobj = container_of(kref,
528 						   struct drm_syncobj,
529 						   refcount);
530 	struct syncobj_eventfd_entry *ev_fd_cur, *ev_fd_tmp;
531 
532 	drm_syncobj_replace_fence(syncobj, NULL);
533 
534 	list_for_each_entry_safe(ev_fd_cur, ev_fd_tmp, &syncobj->ev_fd_list, node)
535 		syncobj_eventfd_entry_free(ev_fd_cur);
536 
537 	kfree(syncobj);
538 }
539 EXPORT_SYMBOL(drm_syncobj_free);
540 
541 /**
542  * drm_syncobj_create - create a new syncobj
543  * @out_syncobj: returned syncobj
544  * @flags: DRM_SYNCOBJ_* flags
545  * @fence: if non-NULL, the syncobj will represent this fence
546  *
547  * This is the first function to create a sync object. After creating, drivers
548  * probably want to make it available to userspace, either through
549  * drm_syncobj_get_handle() or drm_syncobj_get_fd().
550  *
551  * Returns 0 on success or a negative error value on failure.
552  */
553 int drm_syncobj_create(struct drm_syncobj **out_syncobj, uint32_t flags,
554 		       struct dma_fence *fence)
555 {
556 	int ret;
557 	struct drm_syncobj *syncobj;
558 
559 	syncobj = kzalloc(sizeof(struct drm_syncobj), GFP_KERNEL);
560 	if (!syncobj)
561 		return -ENOMEM;
562 
563 	kref_init(&syncobj->refcount);
564 	INIT_LIST_HEAD(&syncobj->cb_list);
565 	INIT_LIST_HEAD(&syncobj->ev_fd_list);
566 	spin_lock_init(&syncobj->lock);
567 
568 	if (flags & DRM_SYNCOBJ_CREATE_SIGNALED) {
569 		ret = drm_syncobj_assign_null_handle(syncobj);
570 		if (ret < 0) {
571 			drm_syncobj_put(syncobj);
572 			return ret;
573 		}
574 	}
575 
576 	if (fence)
577 		drm_syncobj_replace_fence(syncobj, fence);
578 
579 	*out_syncobj = syncobj;
580 	return 0;
581 }
582 EXPORT_SYMBOL(drm_syncobj_create);
583 
584 /**
585  * drm_syncobj_get_handle - get a handle from a syncobj
586  * @file_private: drm file private pointer
587  * @syncobj: Sync object to export
588  * @handle: out parameter with the new handle
589  *
590  * Exports a sync object created with drm_syncobj_create() as a handle on
591  * @file_private to userspace.
592  *
593  * Returns 0 on success or a negative error value on failure.
594  */
595 int drm_syncobj_get_handle(struct drm_file *file_private,
596 			   struct drm_syncobj *syncobj, u32 *handle)
597 {
598 	int ret;
599 
600 	/* take a reference to put in the idr */
601 	drm_syncobj_get(syncobj);
602 
603 	idr_preload(GFP_KERNEL);
604 	spin_lock(&file_private->syncobj_table_lock);
605 	ret = idr_alloc(&file_private->syncobj_idr, syncobj, 1, 0, GFP_NOWAIT);
606 	spin_unlock(&file_private->syncobj_table_lock);
607 
608 	idr_preload_end();
609 
610 	if (ret < 0) {
611 		drm_syncobj_put(syncobj);
612 		return ret;
613 	}
614 
615 	*handle = ret;
616 	return 0;
617 }
618 EXPORT_SYMBOL(drm_syncobj_get_handle);
619 
620 static int drm_syncobj_create_as_handle(struct drm_file *file_private,
621 					u32 *handle, uint32_t flags)
622 {
623 	int ret;
624 	struct drm_syncobj *syncobj;
625 
626 	ret = drm_syncobj_create(&syncobj, flags, NULL);
627 	if (ret)
628 		return ret;
629 
630 	ret = drm_syncobj_get_handle(file_private, syncobj, handle);
631 	drm_syncobj_put(syncobj);
632 	return ret;
633 }
634 
635 static int drm_syncobj_destroy(struct drm_file *file_private,
636 			       u32 handle)
637 {
638 	struct drm_syncobj *syncobj;
639 
640 	spin_lock(&file_private->syncobj_table_lock);
641 	syncobj = idr_remove(&file_private->syncobj_idr, handle);
642 	spin_unlock(&file_private->syncobj_table_lock);
643 
644 	if (!syncobj)
645 		return -EINVAL;
646 
647 	drm_syncobj_put(syncobj);
648 	return 0;
649 }
650 
651 static int drm_syncobj_file_release(struct inode *inode, struct file *file)
652 {
653 	struct drm_syncobj *syncobj = file->private_data;
654 
655 	drm_syncobj_put(syncobj);
656 	return 0;
657 }
658 
659 static const struct file_operations drm_syncobj_file_fops = {
660 	.release = drm_syncobj_file_release,
661 };
662 
663 /**
664  * drm_syncobj_get_fd - get a file descriptor from a syncobj
665  * @syncobj: Sync object to export
666  * @p_fd: out parameter with the new file descriptor
667  *
668  * Exports a sync object created with drm_syncobj_create() as a file descriptor.
669  *
670  * Returns 0 on success or a negative error value on failure.
671  */
672 int drm_syncobj_get_fd(struct drm_syncobj *syncobj, int *p_fd)
673 {
674 	struct file *file;
675 	int fd;
676 
677 	fd = get_unused_fd_flags(O_CLOEXEC);
678 	if (fd < 0)
679 		return fd;
680 
681 	file = anon_inode_getfile("syncobj_file",
682 				  &drm_syncobj_file_fops,
683 				  syncobj, 0);
684 	if (IS_ERR(file)) {
685 		put_unused_fd(fd);
686 		return PTR_ERR(file);
687 	}
688 
689 	drm_syncobj_get(syncobj);
690 	fd_install(fd, file);
691 
692 	*p_fd = fd;
693 	return 0;
694 }
695 EXPORT_SYMBOL(drm_syncobj_get_fd);
696 
697 static int drm_syncobj_handle_to_fd(struct drm_file *file_private,
698 				    u32 handle, int *p_fd)
699 {
700 	struct drm_syncobj *syncobj = drm_syncobj_find(file_private, handle);
701 	int ret;
702 
703 	if (!syncobj)
704 		return -EINVAL;
705 
706 	ret = drm_syncobj_get_fd(syncobj, p_fd);
707 	drm_syncobj_put(syncobj);
708 	return ret;
709 }
710 
711 static int drm_syncobj_fd_to_handle(struct drm_file *file_private,
712 				    int fd, u32 *handle)
713 {
714 	struct drm_syncobj *syncobj;
715 	CLASS(fd, f)(fd);
716 	int ret;
717 
718 	if (fd_empty(f))
719 		return -EINVAL;
720 
721 	if (fd_file(f)->f_op != &drm_syncobj_file_fops)
722 		return -EINVAL;
723 
724 	/* take a reference to put in the idr */
725 	syncobj = fd_file(f)->private_data;
726 	drm_syncobj_get(syncobj);
727 
728 	idr_preload(GFP_KERNEL);
729 	spin_lock(&file_private->syncobj_table_lock);
730 	ret = idr_alloc(&file_private->syncobj_idr, syncobj, 1, 0, GFP_NOWAIT);
731 	spin_unlock(&file_private->syncobj_table_lock);
732 	idr_preload_end();
733 
734 	if (ret > 0) {
735 		*handle = ret;
736 		ret = 0;
737 	} else
738 		drm_syncobj_put(syncobj);
739 
740 	return ret;
741 }
742 
743 static int drm_syncobj_import_sync_file_fence(struct drm_file *file_private,
744 					      int fd, int handle, u64 point)
745 {
746 	struct dma_fence *fence = sync_file_get_fence(fd);
747 	struct drm_syncobj *syncobj;
748 
749 	if (!fence)
750 		return -EINVAL;
751 
752 	syncobj = drm_syncobj_find(file_private, handle);
753 	if (!syncobj) {
754 		dma_fence_put(fence);
755 		return -ENOENT;
756 	}
757 
758 	if (point) {
759 		struct dma_fence_chain *chain = dma_fence_chain_alloc();
760 
761 		if (!chain)
762 			return -ENOMEM;
763 
764 		drm_syncobj_add_point(syncobj, chain, fence, point);
765 	} else {
766 		drm_syncobj_replace_fence(syncobj, fence);
767 	}
768 
769 	dma_fence_put(fence);
770 	drm_syncobj_put(syncobj);
771 	return 0;
772 }
773 
774 static int drm_syncobj_export_sync_file(struct drm_file *file_private,
775 					int handle, u64 point, int *p_fd)
776 {
777 	int ret;
778 	struct dma_fence *fence;
779 	struct sync_file *sync_file;
780 	int fd = get_unused_fd_flags(O_CLOEXEC);
781 
782 	if (fd < 0)
783 		return fd;
784 
785 	ret = drm_syncobj_find_fence(file_private, handle, point, 0, &fence);
786 	if (ret)
787 		goto err_put_fd;
788 
789 	sync_file = sync_file_create(fence);
790 
791 	dma_fence_put(fence);
792 
793 	if (!sync_file) {
794 		ret = -EINVAL;
795 		goto err_put_fd;
796 	}
797 
798 	fd_install(fd, sync_file->file);
799 
800 	*p_fd = fd;
801 	return 0;
802 err_put_fd:
803 	put_unused_fd(fd);
804 	return ret;
805 }
806 /**
807  * drm_syncobj_open - initializes syncobj file-private structures at devnode open time
808  * @file_private: drm file-private structure to set up
809  *
810  * Called at device open time, sets up the structure for handling refcounting
811  * of sync objects.
812  */
813 void
814 drm_syncobj_open(struct drm_file *file_private)
815 {
816 	idr_init_base(&file_private->syncobj_idr, 1);
817 	spin_lock_init(&file_private->syncobj_table_lock);
818 }
819 
820 static int
821 drm_syncobj_release_handle(int id, void *ptr, void *data)
822 {
823 	struct drm_syncobj *syncobj = ptr;
824 
825 	drm_syncobj_put(syncobj);
826 	return 0;
827 }
828 
829 /**
830  * drm_syncobj_release - release file-private sync object resources
831  * @file_private: drm file-private structure to clean up
832  *
833  * Called at close time when the filp is going away.
834  *
835  * Releases any remaining references on objects by this filp.
836  */
837 void
838 drm_syncobj_release(struct drm_file *file_private)
839 {
840 	idr_for_each(&file_private->syncobj_idr,
841 		     &drm_syncobj_release_handle, file_private);
842 	idr_destroy(&file_private->syncobj_idr);
843 }
844 
845 int
846 drm_syncobj_create_ioctl(struct drm_device *dev, void *data,
847 			 struct drm_file *file_private)
848 {
849 	struct drm_syncobj_create *args = data;
850 
851 	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
852 		return -EOPNOTSUPP;
853 
854 	/* no valid flags yet */
855 	if (args->flags & ~DRM_SYNCOBJ_CREATE_SIGNALED)
856 		return -EINVAL;
857 
858 	return drm_syncobj_create_as_handle(file_private,
859 					    &args->handle, args->flags);
860 }
861 
862 int
863 drm_syncobj_destroy_ioctl(struct drm_device *dev, void *data,
864 			  struct drm_file *file_private)
865 {
866 	struct drm_syncobj_destroy *args = data;
867 
868 	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
869 		return -EOPNOTSUPP;
870 
871 	/* make sure padding is empty */
872 	if (args->pad)
873 		return -EINVAL;
874 	return drm_syncobj_destroy(file_private, args->handle);
875 }
876 
877 int
878 drm_syncobj_handle_to_fd_ioctl(struct drm_device *dev, void *data,
879 				   struct drm_file *file_private)
880 {
881 	struct drm_syncobj_handle *args = data;
882 	unsigned int valid_flags = DRM_SYNCOBJ_HANDLE_TO_FD_FLAGS_TIMELINE |
883 				   DRM_SYNCOBJ_HANDLE_TO_FD_FLAGS_EXPORT_SYNC_FILE;
884 	u64 point = 0;
885 
886 	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
887 		return -EOPNOTSUPP;
888 
889 	if (args->pad)
890 		return -EINVAL;
891 
892 	if (args->flags & ~valid_flags)
893 		return -EINVAL;
894 
895 	if (args->flags & DRM_SYNCOBJ_HANDLE_TO_FD_FLAGS_TIMELINE)
896 		point = args->point;
897 
898 	if (args->flags & DRM_SYNCOBJ_HANDLE_TO_FD_FLAGS_EXPORT_SYNC_FILE)
899 		return drm_syncobj_export_sync_file(file_private, args->handle,
900 						    point, &args->fd);
901 
902 	if (args->point)
903 		return -EINVAL;
904 
905 	return drm_syncobj_handle_to_fd(file_private, args->handle,
906 					&args->fd);
907 }
908 
909 int
910 drm_syncobj_fd_to_handle_ioctl(struct drm_device *dev, void *data,
911 				   struct drm_file *file_private)
912 {
913 	struct drm_syncobj_handle *args = data;
914 	unsigned int valid_flags = DRM_SYNCOBJ_FD_TO_HANDLE_FLAGS_TIMELINE |
915 				   DRM_SYNCOBJ_FD_TO_HANDLE_FLAGS_IMPORT_SYNC_FILE;
916 	u64 point = 0;
917 
918 	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
919 		return -EOPNOTSUPP;
920 
921 	if (args->pad)
922 		return -EINVAL;
923 
924 	if (args->flags & ~valid_flags)
925 		return -EINVAL;
926 
927 	if (args->flags & DRM_SYNCOBJ_FD_TO_HANDLE_FLAGS_TIMELINE)
928 		point = args->point;
929 
930 	if (args->flags & DRM_SYNCOBJ_FD_TO_HANDLE_FLAGS_IMPORT_SYNC_FILE)
931 		return drm_syncobj_import_sync_file_fence(file_private,
932 							  args->fd,
933 							  args->handle,
934 							  point);
935 
936 	if (args->point)
937 		return -EINVAL;
938 
939 	return drm_syncobj_fd_to_handle(file_private, args->fd,
940 					&args->handle);
941 }
942 
943 static int drm_syncobj_transfer_to_timeline(struct drm_file *file_private,
944 					    struct drm_syncobj_transfer *args)
945 {
946 	struct drm_syncobj *timeline_syncobj = NULL;
947 	struct dma_fence *fence, *tmp;
948 	struct dma_fence_chain *chain;
949 	int ret;
950 
951 	timeline_syncobj = drm_syncobj_find(file_private, args->dst_handle);
952 	if (!timeline_syncobj) {
953 		return -ENOENT;
954 	}
955 	ret = drm_syncobj_find_fence(file_private, args->src_handle,
956 				     args->src_point, args->flags,
957 				     &tmp);
958 	if (ret)
959 		goto err_put_timeline;
960 
961 	fence = dma_fence_unwrap_merge(tmp);
962 	dma_fence_put(tmp);
963 	if (!fence) {
964 		ret = -ENOMEM;
965 		goto err_put_timeline;
966 	}
967 
968 	chain = dma_fence_chain_alloc();
969 	if (!chain) {
970 		ret = -ENOMEM;
971 		goto err_free_fence;
972 	}
973 
974 	drm_syncobj_add_point(timeline_syncobj, chain, fence, args->dst_point);
975 err_free_fence:
976 	dma_fence_put(fence);
977 err_put_timeline:
978 	drm_syncobj_put(timeline_syncobj);
979 
980 	return ret;
981 }
982 
983 static int
984 drm_syncobj_transfer_to_binary(struct drm_file *file_private,
985 			       struct drm_syncobj_transfer *args)
986 {
987 	struct drm_syncobj *binary_syncobj = NULL;
988 	struct dma_fence *fence;
989 	int ret;
990 
991 	binary_syncobj = drm_syncobj_find(file_private, args->dst_handle);
992 	if (!binary_syncobj)
993 		return -ENOENT;
994 	ret = drm_syncobj_find_fence(file_private, args->src_handle,
995 				     args->src_point, args->flags, &fence);
996 	if (ret)
997 		goto err;
998 	drm_syncobj_replace_fence(binary_syncobj, fence);
999 	dma_fence_put(fence);
1000 err:
1001 	drm_syncobj_put(binary_syncobj);
1002 
1003 	return ret;
1004 }
1005 int
1006 drm_syncobj_transfer_ioctl(struct drm_device *dev, void *data,
1007 			   struct drm_file *file_private)
1008 {
1009 	struct drm_syncobj_transfer *args = data;
1010 	int ret;
1011 
1012 	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ_TIMELINE))
1013 		return -EOPNOTSUPP;
1014 
1015 	if (args->pad)
1016 		return -EINVAL;
1017 
1018 	if (args->dst_point)
1019 		ret = drm_syncobj_transfer_to_timeline(file_private, args);
1020 	else
1021 		ret = drm_syncobj_transfer_to_binary(file_private, args);
1022 
1023 	return ret;
1024 }
1025 
1026 static void syncobj_wait_fence_func(struct dma_fence *fence,
1027 				    struct dma_fence_cb *cb)
1028 {
1029 	struct syncobj_wait_entry *wait =
1030 		container_of(cb, struct syncobj_wait_entry, fence_cb);
1031 
1032 	wake_up_process(wait->task);
1033 }
1034 
1035 static void syncobj_wait_syncobj_func(struct drm_syncobj *syncobj,
1036 				      struct syncobj_wait_entry *wait)
1037 {
1038 	struct dma_fence *fence;
1039 
1040 	/* This happens inside the syncobj lock */
1041 	fence = rcu_dereference_protected(syncobj->fence,
1042 					  lockdep_is_held(&syncobj->lock));
1043 	dma_fence_get(fence);
1044 	if (!fence || dma_fence_chain_find_seqno(&fence, wait->point)) {
1045 		dma_fence_put(fence);
1046 		return;
1047 	} else if (!fence) {
1048 		wait->fence = dma_fence_get_stub();
1049 	} else {
1050 		wait->fence = fence;
1051 	}
1052 
1053 	wake_up_process(wait->task);
1054 	list_del_init(&wait->node);
1055 }
1056 
1057 static signed long drm_syncobj_array_wait_timeout(struct drm_syncobj **syncobjs,
1058 						  void __user *user_points,
1059 						  uint32_t count,
1060 						  uint32_t flags,
1061 						  signed long timeout,
1062 						  uint32_t *idx,
1063 						  ktime_t *deadline)
1064 {
1065 	struct syncobj_wait_entry *entries;
1066 	struct dma_fence *fence;
1067 	uint64_t *points;
1068 	uint32_t signaled_count, i;
1069 
1070 	if (flags & (DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT |
1071 		     DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE)) {
1072 		might_sleep();
1073 		lockdep_assert_none_held_once();
1074 	}
1075 
1076 	points = kmalloc_array(count, sizeof(*points), GFP_KERNEL);
1077 	if (points == NULL)
1078 		return -ENOMEM;
1079 
1080 	if (!user_points) {
1081 		memset(points, 0, count * sizeof(uint64_t));
1082 
1083 	} else if (copy_from_user(points, user_points,
1084 				  sizeof(uint64_t) * count)) {
1085 		timeout = -EFAULT;
1086 		goto err_free_points;
1087 	}
1088 
1089 	entries = kcalloc(count, sizeof(*entries), GFP_KERNEL);
1090 	if (!entries) {
1091 		timeout = -ENOMEM;
1092 		goto err_free_points;
1093 	}
1094 	/* Walk the list of sync objects and initialize entries.  We do
1095 	 * this up-front so that we can properly return -EINVAL if there is
1096 	 * a syncobj with a missing fence and then never have the chance of
1097 	 * returning -EINVAL again.
1098 	 */
1099 	signaled_count = 0;
1100 	for (i = 0; i < count; ++i) {
1101 		struct dma_fence *fence;
1102 
1103 		entries[i].task = current;
1104 		entries[i].point = points[i];
1105 		fence = drm_syncobj_fence_get(syncobjs[i]);
1106 		if (!fence || dma_fence_chain_find_seqno(&fence, points[i])) {
1107 			dma_fence_put(fence);
1108 			if (flags & (DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT |
1109 				     DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE)) {
1110 				continue;
1111 			} else {
1112 				timeout = -EINVAL;
1113 				goto cleanup_entries;
1114 			}
1115 		}
1116 
1117 		if (fence)
1118 			entries[i].fence = fence;
1119 		else
1120 			entries[i].fence = dma_fence_get_stub();
1121 
1122 		if ((flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE) ||
1123 		    dma_fence_is_signaled(entries[i].fence)) {
1124 			if (signaled_count == 0 && idx)
1125 				*idx = i;
1126 			signaled_count++;
1127 		}
1128 	}
1129 
1130 	if (signaled_count == count ||
1131 	    (signaled_count > 0 &&
1132 	     !(flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL)))
1133 		goto cleanup_entries;
1134 
1135 	/* There's a very annoying laxness in the dma_fence API here, in
1136 	 * that backends are not required to automatically report when a
1137 	 * fence is signaled prior to fence->ops->enable_signaling() being
1138 	 * called.  So here if we fail to match signaled_count, we need to
1139 	 * fallthough and try a 0 timeout wait!
1140 	 */
1141 
1142 	if (flags & (DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT |
1143 		     DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE)) {
1144 		for (i = 0; i < count; ++i)
1145 			drm_syncobj_fence_add_wait(syncobjs[i], &entries[i]);
1146 	}
1147 
1148 	if (deadline) {
1149 		for (i = 0; i < count; ++i) {
1150 			fence = entries[i].fence;
1151 			if (!fence)
1152 				continue;
1153 			dma_fence_set_deadline(fence, *deadline);
1154 		}
1155 	}
1156 
1157 	do {
1158 		set_current_state(TASK_INTERRUPTIBLE);
1159 
1160 		signaled_count = 0;
1161 		for (i = 0; i < count; ++i) {
1162 			fence = entries[i].fence;
1163 			if (!fence)
1164 				continue;
1165 
1166 			if ((flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE) ||
1167 			    dma_fence_is_signaled(fence) ||
1168 			    (!entries[i].fence_cb.func &&
1169 			     dma_fence_add_callback(fence,
1170 						    &entries[i].fence_cb,
1171 						    syncobj_wait_fence_func))) {
1172 				/* The fence has been signaled */
1173 				if (flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL) {
1174 					signaled_count++;
1175 				} else {
1176 					if (idx)
1177 						*idx = i;
1178 					goto done_waiting;
1179 				}
1180 			}
1181 		}
1182 
1183 		if (signaled_count == count)
1184 			goto done_waiting;
1185 
1186 		if (timeout == 0) {
1187 			timeout = -ETIME;
1188 			goto done_waiting;
1189 		}
1190 
1191 		if (signal_pending(current)) {
1192 			timeout = -ERESTARTSYS;
1193 			goto done_waiting;
1194 		}
1195 
1196 		timeout = schedule_timeout(timeout);
1197 	} while (1);
1198 
1199 done_waiting:
1200 	__set_current_state(TASK_RUNNING);
1201 
1202 cleanup_entries:
1203 	for (i = 0; i < count; ++i) {
1204 		drm_syncobj_remove_wait(syncobjs[i], &entries[i]);
1205 		if (entries[i].fence_cb.func)
1206 			dma_fence_remove_callback(entries[i].fence,
1207 						  &entries[i].fence_cb);
1208 		dma_fence_put(entries[i].fence);
1209 	}
1210 	kfree(entries);
1211 
1212 err_free_points:
1213 	kfree(points);
1214 
1215 	return timeout;
1216 }
1217 
1218 /**
1219  * drm_timeout_abs_to_jiffies - calculate jiffies timeout from absolute value
1220  *
1221  * @timeout_nsec: timeout nsec component in ns, 0 for poll
1222  *
1223  * Calculate the timeout in jiffies from an absolute time in sec/nsec.
1224  */
1225 signed long drm_timeout_abs_to_jiffies(int64_t timeout_nsec)
1226 {
1227 	ktime_t abs_timeout, now;
1228 	u64 timeout_ns, timeout_jiffies64;
1229 
1230 	/* make 0 timeout means poll - absolute 0 doesn't seem valid */
1231 	if (timeout_nsec == 0)
1232 		return 0;
1233 
1234 	abs_timeout = ns_to_ktime(timeout_nsec);
1235 	now = ktime_get();
1236 
1237 	if (!ktime_after(abs_timeout, now))
1238 		return 0;
1239 
1240 	timeout_ns = ktime_to_ns(ktime_sub(abs_timeout, now));
1241 
1242 	timeout_jiffies64 = nsecs_to_jiffies64(timeout_ns);
1243 	/*  clamp timeout to avoid infinite timeout */
1244 	if (timeout_jiffies64 >= MAX_SCHEDULE_TIMEOUT - 1)
1245 		return MAX_SCHEDULE_TIMEOUT - 1;
1246 
1247 	return timeout_jiffies64 + 1;
1248 }
1249 EXPORT_SYMBOL(drm_timeout_abs_to_jiffies);
1250 
1251 static int drm_syncobj_array_wait(struct drm_device *dev,
1252 				  struct drm_file *file_private,
1253 				  struct drm_syncobj_wait *wait,
1254 				  struct drm_syncobj_timeline_wait *timeline_wait,
1255 				  struct drm_syncobj **syncobjs, bool timeline,
1256 				  ktime_t *deadline)
1257 {
1258 	signed long timeout = 0;
1259 	uint32_t first = ~0;
1260 
1261 	if (!timeline) {
1262 		timeout = drm_timeout_abs_to_jiffies(wait->timeout_nsec);
1263 		timeout = drm_syncobj_array_wait_timeout(syncobjs,
1264 							 NULL,
1265 							 wait->count_handles,
1266 							 wait->flags,
1267 							 timeout, &first,
1268 							 deadline);
1269 		if (timeout < 0)
1270 			return timeout;
1271 		wait->first_signaled = first;
1272 	} else {
1273 		timeout = drm_timeout_abs_to_jiffies(timeline_wait->timeout_nsec);
1274 		timeout = drm_syncobj_array_wait_timeout(syncobjs,
1275 							 u64_to_user_ptr(timeline_wait->points),
1276 							 timeline_wait->count_handles,
1277 							 timeline_wait->flags,
1278 							 timeout, &first,
1279 							 deadline);
1280 		if (timeout < 0)
1281 			return timeout;
1282 		timeline_wait->first_signaled = first;
1283 	}
1284 	return 0;
1285 }
1286 
1287 static int drm_syncobj_array_find(struct drm_file *file_private,
1288 				  void __user *user_handles,
1289 				  uint32_t count_handles,
1290 				  struct drm_syncobj ***syncobjs_out)
1291 {
1292 	uint32_t i, *handles;
1293 	struct drm_syncobj **syncobjs;
1294 	int ret;
1295 
1296 	handles = kmalloc_array(count_handles, sizeof(*handles), GFP_KERNEL);
1297 	if (handles == NULL)
1298 		return -ENOMEM;
1299 
1300 	if (copy_from_user(handles, user_handles,
1301 			   sizeof(uint32_t) * count_handles)) {
1302 		ret = -EFAULT;
1303 		goto err_free_handles;
1304 	}
1305 
1306 	syncobjs = kmalloc_array(count_handles, sizeof(*syncobjs), GFP_KERNEL);
1307 	if (syncobjs == NULL) {
1308 		ret = -ENOMEM;
1309 		goto err_free_handles;
1310 	}
1311 
1312 	for (i = 0; i < count_handles; i++) {
1313 		syncobjs[i] = drm_syncobj_find(file_private, handles[i]);
1314 		if (!syncobjs[i]) {
1315 			ret = -ENOENT;
1316 			goto err_put_syncobjs;
1317 		}
1318 	}
1319 
1320 	kfree(handles);
1321 	*syncobjs_out = syncobjs;
1322 	return 0;
1323 
1324 err_put_syncobjs:
1325 	while (i-- > 0)
1326 		drm_syncobj_put(syncobjs[i]);
1327 	kfree(syncobjs);
1328 err_free_handles:
1329 	kfree(handles);
1330 
1331 	return ret;
1332 }
1333 
1334 static void drm_syncobj_array_free(struct drm_syncobj **syncobjs,
1335 				   uint32_t count)
1336 {
1337 	uint32_t i;
1338 
1339 	for (i = 0; i < count; i++)
1340 		drm_syncobj_put(syncobjs[i]);
1341 	kfree(syncobjs);
1342 }
1343 
1344 int
1345 drm_syncobj_wait_ioctl(struct drm_device *dev, void *data,
1346 		       struct drm_file *file_private)
1347 {
1348 	struct drm_syncobj_wait *args = data;
1349 	struct drm_syncobj **syncobjs;
1350 	unsigned int possible_flags;
1351 	ktime_t t, *tp = NULL;
1352 	int ret = 0;
1353 
1354 	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
1355 		return -EOPNOTSUPP;
1356 
1357 	possible_flags = DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL |
1358 			 DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT |
1359 			 DRM_SYNCOBJ_WAIT_FLAGS_WAIT_DEADLINE;
1360 
1361 	if (args->flags & ~possible_flags)
1362 		return -EINVAL;
1363 
1364 	if (args->count_handles == 0)
1365 		return 0;
1366 
1367 	ret = drm_syncobj_array_find(file_private,
1368 				     u64_to_user_ptr(args->handles),
1369 				     args->count_handles,
1370 				     &syncobjs);
1371 	if (ret < 0)
1372 		return ret;
1373 
1374 	if (args->flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_DEADLINE) {
1375 		t = ns_to_ktime(args->deadline_nsec);
1376 		tp = &t;
1377 	}
1378 
1379 	ret = drm_syncobj_array_wait(dev, file_private,
1380 				     args, NULL, syncobjs, false, tp);
1381 
1382 	drm_syncobj_array_free(syncobjs, args->count_handles);
1383 
1384 	return ret;
1385 }
1386 
1387 int
1388 drm_syncobj_timeline_wait_ioctl(struct drm_device *dev, void *data,
1389 				struct drm_file *file_private)
1390 {
1391 	struct drm_syncobj_timeline_wait *args = data;
1392 	struct drm_syncobj **syncobjs;
1393 	unsigned int possible_flags;
1394 	ktime_t t, *tp = NULL;
1395 	int ret = 0;
1396 
1397 	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ_TIMELINE))
1398 		return -EOPNOTSUPP;
1399 
1400 	possible_flags = DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL |
1401 			 DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT |
1402 			 DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE |
1403 			 DRM_SYNCOBJ_WAIT_FLAGS_WAIT_DEADLINE;
1404 
1405 	if (args->flags & ~possible_flags)
1406 		return -EINVAL;
1407 
1408 	if (args->count_handles == 0)
1409 		return 0;
1410 
1411 	ret = drm_syncobj_array_find(file_private,
1412 				     u64_to_user_ptr(args->handles),
1413 				     args->count_handles,
1414 				     &syncobjs);
1415 	if (ret < 0)
1416 		return ret;
1417 
1418 	if (args->flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_DEADLINE) {
1419 		t = ns_to_ktime(args->deadline_nsec);
1420 		tp = &t;
1421 	}
1422 
1423 	ret = drm_syncobj_array_wait(dev, file_private,
1424 				     NULL, args, syncobjs, true, tp);
1425 
1426 	drm_syncobj_array_free(syncobjs, args->count_handles);
1427 
1428 	return ret;
1429 }
1430 
1431 static void syncobj_eventfd_entry_fence_func(struct dma_fence *fence,
1432 					     struct dma_fence_cb *cb)
1433 {
1434 	struct syncobj_eventfd_entry *entry =
1435 		container_of(cb, struct syncobj_eventfd_entry, fence_cb);
1436 
1437 	eventfd_signal(entry->ev_fd_ctx);
1438 	syncobj_eventfd_entry_free(entry);
1439 }
1440 
1441 static void
1442 syncobj_eventfd_entry_func(struct drm_syncobj *syncobj,
1443 			   struct syncobj_eventfd_entry *entry)
1444 {
1445 	int ret;
1446 	struct dma_fence *fence;
1447 
1448 	/* This happens inside the syncobj lock */
1449 	fence = dma_fence_get(rcu_dereference_protected(syncobj->fence, 1));
1450 	if (!fence)
1451 		return;
1452 
1453 	ret = dma_fence_chain_find_seqno(&fence, entry->point);
1454 	if (ret != 0) {
1455 		/* The given seqno has not been submitted yet. */
1456 		dma_fence_put(fence);
1457 		return;
1458 	} else if (!fence) {
1459 		/* If dma_fence_chain_find_seqno returns 0 but sets the fence
1460 		 * to NULL, it implies that the given seqno is signaled and a
1461 		 * later seqno has already been submitted. Assign a stub fence
1462 		 * so that the eventfd still gets signaled below.
1463 		 */
1464 		fence = dma_fence_get_stub();
1465 	}
1466 
1467 	list_del_init(&entry->node);
1468 	entry->fence = fence;
1469 
1470 	if (entry->flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE) {
1471 		eventfd_signal(entry->ev_fd_ctx);
1472 		syncobj_eventfd_entry_free(entry);
1473 	} else {
1474 		ret = dma_fence_add_callback(fence, &entry->fence_cb,
1475 					     syncobj_eventfd_entry_fence_func);
1476 		if (ret == -ENOENT) {
1477 			eventfd_signal(entry->ev_fd_ctx);
1478 			syncobj_eventfd_entry_free(entry);
1479 		}
1480 	}
1481 }
1482 
1483 int
1484 drm_syncobj_eventfd_ioctl(struct drm_device *dev, void *data,
1485 			  struct drm_file *file_private)
1486 {
1487 	struct drm_syncobj_eventfd *args = data;
1488 	struct drm_syncobj *syncobj;
1489 	struct eventfd_ctx *ev_fd_ctx;
1490 	struct syncobj_eventfd_entry *entry;
1491 	int ret;
1492 
1493 	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ_TIMELINE))
1494 		return -EOPNOTSUPP;
1495 
1496 	if (args->flags & ~DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE)
1497 		return -EINVAL;
1498 
1499 	if (args->pad)
1500 		return -EINVAL;
1501 
1502 	syncobj = drm_syncobj_find(file_private, args->handle);
1503 	if (!syncobj)
1504 		return -ENOENT;
1505 
1506 	ev_fd_ctx = eventfd_ctx_fdget(args->fd);
1507 	if (IS_ERR(ev_fd_ctx)) {
1508 		ret = PTR_ERR(ev_fd_ctx);
1509 		goto err_fdget;
1510 	}
1511 
1512 	entry = kzalloc(sizeof(*entry), GFP_KERNEL);
1513 	if (!entry) {
1514 		ret = -ENOMEM;
1515 		goto err_kzalloc;
1516 	}
1517 	entry->syncobj = syncobj;
1518 	entry->ev_fd_ctx = ev_fd_ctx;
1519 	entry->point = args->point;
1520 	entry->flags = args->flags;
1521 
1522 	drm_syncobj_add_eventfd(syncobj, entry);
1523 	drm_syncobj_put(syncobj);
1524 
1525 	return 0;
1526 
1527 err_kzalloc:
1528 	eventfd_ctx_put(ev_fd_ctx);
1529 err_fdget:
1530 	drm_syncobj_put(syncobj);
1531 	return ret;
1532 }
1533 
1534 int
1535 drm_syncobj_reset_ioctl(struct drm_device *dev, void *data,
1536 			struct drm_file *file_private)
1537 {
1538 	struct drm_syncobj_array *args = data;
1539 	struct drm_syncobj **syncobjs;
1540 	uint32_t i;
1541 	int ret;
1542 
1543 	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
1544 		return -EOPNOTSUPP;
1545 
1546 	if (args->pad != 0)
1547 		return -EINVAL;
1548 
1549 	if (args->count_handles == 0)
1550 		return -EINVAL;
1551 
1552 	ret = drm_syncobj_array_find(file_private,
1553 				     u64_to_user_ptr(args->handles),
1554 				     args->count_handles,
1555 				     &syncobjs);
1556 	if (ret < 0)
1557 		return ret;
1558 
1559 	for (i = 0; i < args->count_handles; i++)
1560 		drm_syncobj_replace_fence(syncobjs[i], NULL);
1561 
1562 	drm_syncobj_array_free(syncobjs, args->count_handles);
1563 
1564 	return 0;
1565 }
1566 
1567 int
1568 drm_syncobj_signal_ioctl(struct drm_device *dev, void *data,
1569 			 struct drm_file *file_private)
1570 {
1571 	struct drm_syncobj_array *args = data;
1572 	struct drm_syncobj **syncobjs;
1573 	uint32_t i;
1574 	int ret;
1575 
1576 	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
1577 		return -EOPNOTSUPP;
1578 
1579 	if (args->pad != 0)
1580 		return -EINVAL;
1581 
1582 	if (args->count_handles == 0)
1583 		return -EINVAL;
1584 
1585 	ret = drm_syncobj_array_find(file_private,
1586 				     u64_to_user_ptr(args->handles),
1587 				     args->count_handles,
1588 				     &syncobjs);
1589 	if (ret < 0)
1590 		return ret;
1591 
1592 	for (i = 0; i < args->count_handles; i++) {
1593 		ret = drm_syncobj_assign_null_handle(syncobjs[i]);
1594 		if (ret < 0)
1595 			break;
1596 	}
1597 
1598 	drm_syncobj_array_free(syncobjs, args->count_handles);
1599 
1600 	return ret;
1601 }
1602 
1603 int
1604 drm_syncobj_timeline_signal_ioctl(struct drm_device *dev, void *data,
1605 				  struct drm_file *file_private)
1606 {
1607 	struct drm_syncobj_timeline_array *args = data;
1608 	struct drm_syncobj **syncobjs;
1609 	struct dma_fence_chain **chains;
1610 	uint64_t *points;
1611 	uint32_t i, j;
1612 	int ret;
1613 
1614 	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ_TIMELINE))
1615 		return -EOPNOTSUPP;
1616 
1617 	if (args->flags != 0)
1618 		return -EINVAL;
1619 
1620 	if (args->count_handles == 0)
1621 		return -EINVAL;
1622 
1623 	ret = drm_syncobj_array_find(file_private,
1624 				     u64_to_user_ptr(args->handles),
1625 				     args->count_handles,
1626 				     &syncobjs);
1627 	if (ret < 0)
1628 		return ret;
1629 
1630 	points = kmalloc_array(args->count_handles, sizeof(*points),
1631 			       GFP_KERNEL);
1632 	if (!points) {
1633 		ret = -ENOMEM;
1634 		goto out;
1635 	}
1636 	if (!u64_to_user_ptr(args->points)) {
1637 		memset(points, 0, args->count_handles * sizeof(uint64_t));
1638 	} else if (copy_from_user(points, u64_to_user_ptr(args->points),
1639 				  sizeof(uint64_t) * args->count_handles)) {
1640 		ret = -EFAULT;
1641 		goto err_points;
1642 	}
1643 
1644 	chains = kmalloc_array(args->count_handles, sizeof(void *), GFP_KERNEL);
1645 	if (!chains) {
1646 		ret = -ENOMEM;
1647 		goto err_points;
1648 	}
1649 	for (i = 0; i < args->count_handles; i++) {
1650 		chains[i] = dma_fence_chain_alloc();
1651 		if (!chains[i]) {
1652 			for (j = 0; j < i; j++)
1653 				dma_fence_chain_free(chains[j]);
1654 			ret = -ENOMEM;
1655 			goto err_chains;
1656 		}
1657 	}
1658 
1659 	for (i = 0; i < args->count_handles; i++) {
1660 		struct dma_fence *fence = dma_fence_get_stub();
1661 
1662 		drm_syncobj_add_point(syncobjs[i], chains[i],
1663 				      fence, points[i]);
1664 		dma_fence_put(fence);
1665 	}
1666 err_chains:
1667 	kfree(chains);
1668 err_points:
1669 	kfree(points);
1670 out:
1671 	drm_syncobj_array_free(syncobjs, args->count_handles);
1672 
1673 	return ret;
1674 }
1675 
1676 int drm_syncobj_query_ioctl(struct drm_device *dev, void *data,
1677 			    struct drm_file *file_private)
1678 {
1679 	struct drm_syncobj_timeline_array *args = data;
1680 	struct drm_syncobj **syncobjs;
1681 	uint64_t __user *points = u64_to_user_ptr(args->points);
1682 	uint32_t i;
1683 	int ret;
1684 
1685 	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ_TIMELINE))
1686 		return -EOPNOTSUPP;
1687 
1688 	if (args->flags & ~DRM_SYNCOBJ_QUERY_FLAGS_LAST_SUBMITTED)
1689 		return -EINVAL;
1690 
1691 	if (args->count_handles == 0)
1692 		return -EINVAL;
1693 
1694 	ret = drm_syncobj_array_find(file_private,
1695 				     u64_to_user_ptr(args->handles),
1696 				     args->count_handles,
1697 				     &syncobjs);
1698 	if (ret < 0)
1699 		return ret;
1700 
1701 	for (i = 0; i < args->count_handles; i++) {
1702 		struct dma_fence_chain *chain;
1703 		struct dma_fence *fence;
1704 		uint64_t point;
1705 
1706 		fence = drm_syncobj_fence_get(syncobjs[i]);
1707 		chain = to_dma_fence_chain(fence);
1708 		if (chain) {
1709 			struct dma_fence *iter, *last_signaled =
1710 				dma_fence_get(fence);
1711 
1712 			if (args->flags &
1713 			    DRM_SYNCOBJ_QUERY_FLAGS_LAST_SUBMITTED) {
1714 				point = fence->seqno;
1715 			} else {
1716 				dma_fence_chain_for_each(iter, fence) {
1717 					if (iter->context != fence->context) {
1718 						dma_fence_put(iter);
1719 						/* It is most likely that timeline has
1720 						* unorder points. */
1721 						break;
1722 					}
1723 					dma_fence_put(last_signaled);
1724 					last_signaled = dma_fence_get(iter);
1725 				}
1726 				point = dma_fence_is_signaled(last_signaled) ?
1727 					last_signaled->seqno :
1728 					to_dma_fence_chain(last_signaled)->prev_seqno;
1729 			}
1730 			dma_fence_put(last_signaled);
1731 		} else {
1732 			point = 0;
1733 		}
1734 		dma_fence_put(fence);
1735 		ret = copy_to_user(&points[i], &point, sizeof(uint64_t));
1736 		ret = ret ? -EFAULT : 0;
1737 		if (ret)
1738 			break;
1739 	}
1740 	drm_syncobj_array_free(syncobjs, args->count_handles);
1741 
1742 	return ret;
1743 }
1744