xref: /linux/drivers/gpu/drm/drm_syncobj.c (revision 3fd6c59042dbba50391e30862beac979491145fe)
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  */
drm_syncobj_find(struct drm_file * file_private,u32 handle)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 
drm_syncobj_fence_add_wait(struct drm_syncobj * syncobj,struct syncobj_wait_entry * wait)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 
drm_syncobj_remove_wait(struct drm_syncobj * syncobj,struct syncobj_wait_entry * wait)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
syncobj_eventfd_entry_free(struct syncobj_eventfd_entry * entry)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
drm_syncobj_add_eventfd(struct drm_syncobj * syncobj,struct syncobj_eventfd_entry * entry)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  */
drm_syncobj_add_point(struct drm_syncobj * syncobj,struct dma_fence_chain * chain,struct dma_fence * fence,uint64_t point)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  */
drm_syncobj_replace_fence(struct drm_syncobj * syncobj,struct dma_fence * fence)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  */
drm_syncobj_assign_null_handle(struct drm_syncobj * syncobj)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  */
drm_syncobj_find_fence(struct drm_file * file_private,u32 handle,u64 point,u64 flags,struct dma_fence ** fence)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  */
drm_syncobj_free(struct kref * kref)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  */
drm_syncobj_create(struct drm_syncobj ** out_syncobj,uint32_t flags,struct dma_fence * fence)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  */
drm_syncobj_get_handle(struct drm_file * file_private,struct drm_syncobj * syncobj,u32 * handle)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 
drm_syncobj_create_as_handle(struct drm_file * file_private,u32 * handle,uint32_t flags)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 
drm_syncobj_destroy(struct drm_file * file_private,u32 handle)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 
drm_syncobj_file_release(struct inode * inode,struct file * file)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  */
drm_syncobj_get_fd(struct drm_syncobj * syncobj,int * p_fd)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 
drm_syncobj_handle_to_fd(struct drm_file * file_private,u32 handle,int * p_fd)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 
drm_syncobj_fd_to_handle(struct drm_file * file_private,int fd,u32 * handle)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 
drm_syncobj_import_sync_file_fence(struct drm_file * file_private,int fd,int handle)743 static int drm_syncobj_import_sync_file_fence(struct drm_file *file_private,
744 					      int fd, int handle)
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 	drm_syncobj_replace_fence(syncobj, fence);
759 	dma_fence_put(fence);
760 	drm_syncobj_put(syncobj);
761 	return 0;
762 }
763 
drm_syncobj_export_sync_file(struct drm_file * file_private,int handle,int * p_fd)764 static int drm_syncobj_export_sync_file(struct drm_file *file_private,
765 					int handle, int *p_fd)
766 {
767 	int ret;
768 	struct dma_fence *fence;
769 	struct sync_file *sync_file;
770 	int fd = get_unused_fd_flags(O_CLOEXEC);
771 
772 	if (fd < 0)
773 		return fd;
774 
775 	ret = drm_syncobj_find_fence(file_private, handle, 0, 0, &fence);
776 	if (ret)
777 		goto err_put_fd;
778 
779 	sync_file = sync_file_create(fence);
780 
781 	dma_fence_put(fence);
782 
783 	if (!sync_file) {
784 		ret = -EINVAL;
785 		goto err_put_fd;
786 	}
787 
788 	fd_install(fd, sync_file->file);
789 
790 	*p_fd = fd;
791 	return 0;
792 err_put_fd:
793 	put_unused_fd(fd);
794 	return ret;
795 }
796 /**
797  * drm_syncobj_open - initializes syncobj file-private structures at devnode open time
798  * @file_private: drm file-private structure to set up
799  *
800  * Called at device open time, sets up the structure for handling refcounting
801  * of sync objects.
802  */
803 void
drm_syncobj_open(struct drm_file * file_private)804 drm_syncobj_open(struct drm_file *file_private)
805 {
806 	idr_init_base(&file_private->syncobj_idr, 1);
807 	spin_lock_init(&file_private->syncobj_table_lock);
808 }
809 
810 static int
drm_syncobj_release_handle(int id,void * ptr,void * data)811 drm_syncobj_release_handle(int id, void *ptr, void *data)
812 {
813 	struct drm_syncobj *syncobj = ptr;
814 
815 	drm_syncobj_put(syncobj);
816 	return 0;
817 }
818 
819 /**
820  * drm_syncobj_release - release file-private sync object resources
821  * @file_private: drm file-private structure to clean up
822  *
823  * Called at close time when the filp is going away.
824  *
825  * Releases any remaining references on objects by this filp.
826  */
827 void
drm_syncobj_release(struct drm_file * file_private)828 drm_syncobj_release(struct drm_file *file_private)
829 {
830 	idr_for_each(&file_private->syncobj_idr,
831 		     &drm_syncobj_release_handle, file_private);
832 	idr_destroy(&file_private->syncobj_idr);
833 }
834 
835 int
drm_syncobj_create_ioctl(struct drm_device * dev,void * data,struct drm_file * file_private)836 drm_syncobj_create_ioctl(struct drm_device *dev, void *data,
837 			 struct drm_file *file_private)
838 {
839 	struct drm_syncobj_create *args = data;
840 
841 	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
842 		return -EOPNOTSUPP;
843 
844 	/* no valid flags yet */
845 	if (args->flags & ~DRM_SYNCOBJ_CREATE_SIGNALED)
846 		return -EINVAL;
847 
848 	return drm_syncobj_create_as_handle(file_private,
849 					    &args->handle, args->flags);
850 }
851 
852 int
drm_syncobj_destroy_ioctl(struct drm_device * dev,void * data,struct drm_file * file_private)853 drm_syncobj_destroy_ioctl(struct drm_device *dev, void *data,
854 			  struct drm_file *file_private)
855 {
856 	struct drm_syncobj_destroy *args = data;
857 
858 	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
859 		return -EOPNOTSUPP;
860 
861 	/* make sure padding is empty */
862 	if (args->pad)
863 		return -EINVAL;
864 	return drm_syncobj_destroy(file_private, args->handle);
865 }
866 
867 int
drm_syncobj_handle_to_fd_ioctl(struct drm_device * dev,void * data,struct drm_file * file_private)868 drm_syncobj_handle_to_fd_ioctl(struct drm_device *dev, void *data,
869 				   struct drm_file *file_private)
870 {
871 	struct drm_syncobj_handle *args = data;
872 
873 	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
874 		return -EOPNOTSUPP;
875 
876 	if (args->pad)
877 		return -EINVAL;
878 
879 	if (args->flags != 0 &&
880 	    args->flags != DRM_SYNCOBJ_HANDLE_TO_FD_FLAGS_EXPORT_SYNC_FILE)
881 		return -EINVAL;
882 
883 	if (args->flags & DRM_SYNCOBJ_HANDLE_TO_FD_FLAGS_EXPORT_SYNC_FILE)
884 		return drm_syncobj_export_sync_file(file_private, args->handle,
885 						    &args->fd);
886 
887 	return drm_syncobj_handle_to_fd(file_private, args->handle,
888 					&args->fd);
889 }
890 
891 int
drm_syncobj_fd_to_handle_ioctl(struct drm_device * dev,void * data,struct drm_file * file_private)892 drm_syncobj_fd_to_handle_ioctl(struct drm_device *dev, void *data,
893 				   struct drm_file *file_private)
894 {
895 	struct drm_syncobj_handle *args = data;
896 
897 	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
898 		return -EOPNOTSUPP;
899 
900 	if (args->pad)
901 		return -EINVAL;
902 
903 	if (args->flags != 0 &&
904 	    args->flags != DRM_SYNCOBJ_FD_TO_HANDLE_FLAGS_IMPORT_SYNC_FILE)
905 		return -EINVAL;
906 
907 	if (args->flags & DRM_SYNCOBJ_FD_TO_HANDLE_FLAGS_IMPORT_SYNC_FILE)
908 		return drm_syncobj_import_sync_file_fence(file_private,
909 							  args->fd,
910 							  args->handle);
911 
912 	return drm_syncobj_fd_to_handle(file_private, args->fd,
913 					&args->handle);
914 }
915 
drm_syncobj_transfer_to_timeline(struct drm_file * file_private,struct drm_syncobj_transfer * args)916 static int drm_syncobj_transfer_to_timeline(struct drm_file *file_private,
917 					    struct drm_syncobj_transfer *args)
918 {
919 	struct drm_syncobj *timeline_syncobj = NULL;
920 	struct dma_fence *fence, *tmp;
921 	struct dma_fence_chain *chain;
922 	int ret;
923 
924 	timeline_syncobj = drm_syncobj_find(file_private, args->dst_handle);
925 	if (!timeline_syncobj) {
926 		return -ENOENT;
927 	}
928 	ret = drm_syncobj_find_fence(file_private, args->src_handle,
929 				     args->src_point, args->flags,
930 				     &tmp);
931 	if (ret)
932 		goto err_put_timeline;
933 
934 	fence = dma_fence_unwrap_merge(tmp);
935 	dma_fence_put(tmp);
936 	if (!fence) {
937 		ret = -ENOMEM;
938 		goto err_put_timeline;
939 	}
940 
941 	chain = dma_fence_chain_alloc();
942 	if (!chain) {
943 		ret = -ENOMEM;
944 		goto err_free_fence;
945 	}
946 
947 	drm_syncobj_add_point(timeline_syncobj, chain, fence, args->dst_point);
948 err_free_fence:
949 	dma_fence_put(fence);
950 err_put_timeline:
951 	drm_syncobj_put(timeline_syncobj);
952 
953 	return ret;
954 }
955 
956 static int
drm_syncobj_transfer_to_binary(struct drm_file * file_private,struct drm_syncobj_transfer * args)957 drm_syncobj_transfer_to_binary(struct drm_file *file_private,
958 			       struct drm_syncobj_transfer *args)
959 {
960 	struct drm_syncobj *binary_syncobj = NULL;
961 	struct dma_fence *fence;
962 	int ret;
963 
964 	binary_syncobj = drm_syncobj_find(file_private, args->dst_handle);
965 	if (!binary_syncobj)
966 		return -ENOENT;
967 	ret = drm_syncobj_find_fence(file_private, args->src_handle,
968 				     args->src_point, args->flags, &fence);
969 	if (ret)
970 		goto err;
971 	drm_syncobj_replace_fence(binary_syncobj, fence);
972 	dma_fence_put(fence);
973 err:
974 	drm_syncobj_put(binary_syncobj);
975 
976 	return ret;
977 }
978 int
drm_syncobj_transfer_ioctl(struct drm_device * dev,void * data,struct drm_file * file_private)979 drm_syncobj_transfer_ioctl(struct drm_device *dev, void *data,
980 			   struct drm_file *file_private)
981 {
982 	struct drm_syncobj_transfer *args = data;
983 	int ret;
984 
985 	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ_TIMELINE))
986 		return -EOPNOTSUPP;
987 
988 	if (args->pad)
989 		return -EINVAL;
990 
991 	if (args->dst_point)
992 		ret = drm_syncobj_transfer_to_timeline(file_private, args);
993 	else
994 		ret = drm_syncobj_transfer_to_binary(file_private, args);
995 
996 	return ret;
997 }
998 
syncobj_wait_fence_func(struct dma_fence * fence,struct dma_fence_cb * cb)999 static void syncobj_wait_fence_func(struct dma_fence *fence,
1000 				    struct dma_fence_cb *cb)
1001 {
1002 	struct syncobj_wait_entry *wait =
1003 		container_of(cb, struct syncobj_wait_entry, fence_cb);
1004 
1005 	wake_up_process(wait->task);
1006 }
1007 
syncobj_wait_syncobj_func(struct drm_syncobj * syncobj,struct syncobj_wait_entry * wait)1008 static void syncobj_wait_syncobj_func(struct drm_syncobj *syncobj,
1009 				      struct syncobj_wait_entry *wait)
1010 {
1011 	struct dma_fence *fence;
1012 
1013 	/* This happens inside the syncobj lock */
1014 	fence = rcu_dereference_protected(syncobj->fence,
1015 					  lockdep_is_held(&syncobj->lock));
1016 	dma_fence_get(fence);
1017 	if (!fence || dma_fence_chain_find_seqno(&fence, wait->point)) {
1018 		dma_fence_put(fence);
1019 		return;
1020 	} else if (!fence) {
1021 		wait->fence = dma_fence_get_stub();
1022 	} else {
1023 		wait->fence = fence;
1024 	}
1025 
1026 	wake_up_process(wait->task);
1027 	list_del_init(&wait->node);
1028 }
1029 
drm_syncobj_array_wait_timeout(struct drm_syncobj ** syncobjs,void __user * user_points,uint32_t count,uint32_t flags,signed long timeout,uint32_t * idx,ktime_t * deadline)1030 static signed long drm_syncobj_array_wait_timeout(struct drm_syncobj **syncobjs,
1031 						  void __user *user_points,
1032 						  uint32_t count,
1033 						  uint32_t flags,
1034 						  signed long timeout,
1035 						  uint32_t *idx,
1036 						  ktime_t *deadline)
1037 {
1038 	struct syncobj_wait_entry *entries;
1039 	struct dma_fence *fence;
1040 	uint64_t *points;
1041 	uint32_t signaled_count, i;
1042 
1043 	if (flags & (DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT |
1044 		     DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE)) {
1045 		might_sleep();
1046 		lockdep_assert_none_held_once();
1047 	}
1048 
1049 	points = kmalloc_array(count, sizeof(*points), GFP_KERNEL);
1050 	if (points == NULL)
1051 		return -ENOMEM;
1052 
1053 	if (!user_points) {
1054 		memset(points, 0, count * sizeof(uint64_t));
1055 
1056 	} else if (copy_from_user(points, user_points,
1057 				  sizeof(uint64_t) * count)) {
1058 		timeout = -EFAULT;
1059 		goto err_free_points;
1060 	}
1061 
1062 	entries = kcalloc(count, sizeof(*entries), GFP_KERNEL);
1063 	if (!entries) {
1064 		timeout = -ENOMEM;
1065 		goto err_free_points;
1066 	}
1067 	/* Walk the list of sync objects and initialize entries.  We do
1068 	 * this up-front so that we can properly return -EINVAL if there is
1069 	 * a syncobj with a missing fence and then never have the chance of
1070 	 * returning -EINVAL again.
1071 	 */
1072 	signaled_count = 0;
1073 	for (i = 0; i < count; ++i) {
1074 		struct dma_fence *fence;
1075 
1076 		entries[i].task = current;
1077 		entries[i].point = points[i];
1078 		fence = drm_syncobj_fence_get(syncobjs[i]);
1079 		if (!fence || dma_fence_chain_find_seqno(&fence, points[i])) {
1080 			dma_fence_put(fence);
1081 			if (flags & (DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT |
1082 				     DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE)) {
1083 				continue;
1084 			} else {
1085 				timeout = -EINVAL;
1086 				goto cleanup_entries;
1087 			}
1088 		}
1089 
1090 		if (fence)
1091 			entries[i].fence = fence;
1092 		else
1093 			entries[i].fence = dma_fence_get_stub();
1094 
1095 		if ((flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE) ||
1096 		    dma_fence_is_signaled(entries[i].fence)) {
1097 			if (signaled_count == 0 && idx)
1098 				*idx = i;
1099 			signaled_count++;
1100 		}
1101 	}
1102 
1103 	if (signaled_count == count ||
1104 	    (signaled_count > 0 &&
1105 	     !(flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL)))
1106 		goto cleanup_entries;
1107 
1108 	/* There's a very annoying laxness in the dma_fence API here, in
1109 	 * that backends are not required to automatically report when a
1110 	 * fence is signaled prior to fence->ops->enable_signaling() being
1111 	 * called.  So here if we fail to match signaled_count, we need to
1112 	 * fallthough and try a 0 timeout wait!
1113 	 */
1114 
1115 	if (flags & (DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT |
1116 		     DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE)) {
1117 		for (i = 0; i < count; ++i)
1118 			drm_syncobj_fence_add_wait(syncobjs[i], &entries[i]);
1119 	}
1120 
1121 	if (deadline) {
1122 		for (i = 0; i < count; ++i) {
1123 			fence = entries[i].fence;
1124 			if (!fence)
1125 				continue;
1126 			dma_fence_set_deadline(fence, *deadline);
1127 		}
1128 	}
1129 
1130 	do {
1131 		set_current_state(TASK_INTERRUPTIBLE);
1132 
1133 		signaled_count = 0;
1134 		for (i = 0; i < count; ++i) {
1135 			fence = entries[i].fence;
1136 			if (!fence)
1137 				continue;
1138 
1139 			if ((flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE) ||
1140 			    dma_fence_is_signaled(fence) ||
1141 			    (!entries[i].fence_cb.func &&
1142 			     dma_fence_add_callback(fence,
1143 						    &entries[i].fence_cb,
1144 						    syncobj_wait_fence_func))) {
1145 				/* The fence has been signaled */
1146 				if (flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL) {
1147 					signaled_count++;
1148 				} else {
1149 					if (idx)
1150 						*idx = i;
1151 					goto done_waiting;
1152 				}
1153 			}
1154 		}
1155 
1156 		if (signaled_count == count)
1157 			goto done_waiting;
1158 
1159 		if (timeout == 0) {
1160 			timeout = -ETIME;
1161 			goto done_waiting;
1162 		}
1163 
1164 		if (signal_pending(current)) {
1165 			timeout = -ERESTARTSYS;
1166 			goto done_waiting;
1167 		}
1168 
1169 		timeout = schedule_timeout(timeout);
1170 	} while (1);
1171 
1172 done_waiting:
1173 	__set_current_state(TASK_RUNNING);
1174 
1175 cleanup_entries:
1176 	for (i = 0; i < count; ++i) {
1177 		drm_syncobj_remove_wait(syncobjs[i], &entries[i]);
1178 		if (entries[i].fence_cb.func)
1179 			dma_fence_remove_callback(entries[i].fence,
1180 						  &entries[i].fence_cb);
1181 		dma_fence_put(entries[i].fence);
1182 	}
1183 	kfree(entries);
1184 
1185 err_free_points:
1186 	kfree(points);
1187 
1188 	return timeout;
1189 }
1190 
1191 /**
1192  * drm_timeout_abs_to_jiffies - calculate jiffies timeout from absolute value
1193  *
1194  * @timeout_nsec: timeout nsec component in ns, 0 for poll
1195  *
1196  * Calculate the timeout in jiffies from an absolute time in sec/nsec.
1197  */
drm_timeout_abs_to_jiffies(int64_t timeout_nsec)1198 signed long drm_timeout_abs_to_jiffies(int64_t timeout_nsec)
1199 {
1200 	ktime_t abs_timeout, now;
1201 	u64 timeout_ns, timeout_jiffies64;
1202 
1203 	/* make 0 timeout means poll - absolute 0 doesn't seem valid */
1204 	if (timeout_nsec == 0)
1205 		return 0;
1206 
1207 	abs_timeout = ns_to_ktime(timeout_nsec);
1208 	now = ktime_get();
1209 
1210 	if (!ktime_after(abs_timeout, now))
1211 		return 0;
1212 
1213 	timeout_ns = ktime_to_ns(ktime_sub(abs_timeout, now));
1214 
1215 	timeout_jiffies64 = nsecs_to_jiffies64(timeout_ns);
1216 	/*  clamp timeout to avoid infinite timeout */
1217 	if (timeout_jiffies64 >= MAX_SCHEDULE_TIMEOUT - 1)
1218 		return MAX_SCHEDULE_TIMEOUT - 1;
1219 
1220 	return timeout_jiffies64 + 1;
1221 }
1222 EXPORT_SYMBOL(drm_timeout_abs_to_jiffies);
1223 
drm_syncobj_array_wait(struct drm_device * dev,struct drm_file * file_private,struct drm_syncobj_wait * wait,struct drm_syncobj_timeline_wait * timeline_wait,struct drm_syncobj ** syncobjs,bool timeline,ktime_t * deadline)1224 static int drm_syncobj_array_wait(struct drm_device *dev,
1225 				  struct drm_file *file_private,
1226 				  struct drm_syncobj_wait *wait,
1227 				  struct drm_syncobj_timeline_wait *timeline_wait,
1228 				  struct drm_syncobj **syncobjs, bool timeline,
1229 				  ktime_t *deadline)
1230 {
1231 	signed long timeout = 0;
1232 	uint32_t first = ~0;
1233 
1234 	if (!timeline) {
1235 		timeout = drm_timeout_abs_to_jiffies(wait->timeout_nsec);
1236 		timeout = drm_syncobj_array_wait_timeout(syncobjs,
1237 							 NULL,
1238 							 wait->count_handles,
1239 							 wait->flags,
1240 							 timeout, &first,
1241 							 deadline);
1242 		if (timeout < 0)
1243 			return timeout;
1244 		wait->first_signaled = first;
1245 	} else {
1246 		timeout = drm_timeout_abs_to_jiffies(timeline_wait->timeout_nsec);
1247 		timeout = drm_syncobj_array_wait_timeout(syncobjs,
1248 							 u64_to_user_ptr(timeline_wait->points),
1249 							 timeline_wait->count_handles,
1250 							 timeline_wait->flags,
1251 							 timeout, &first,
1252 							 deadline);
1253 		if (timeout < 0)
1254 			return timeout;
1255 		timeline_wait->first_signaled = first;
1256 	}
1257 	return 0;
1258 }
1259 
drm_syncobj_array_find(struct drm_file * file_private,void __user * user_handles,uint32_t count_handles,struct drm_syncobj *** syncobjs_out)1260 static int drm_syncobj_array_find(struct drm_file *file_private,
1261 				  void __user *user_handles,
1262 				  uint32_t count_handles,
1263 				  struct drm_syncobj ***syncobjs_out)
1264 {
1265 	uint32_t i, *handles;
1266 	struct drm_syncobj **syncobjs;
1267 	int ret;
1268 
1269 	handles = kmalloc_array(count_handles, sizeof(*handles), GFP_KERNEL);
1270 	if (handles == NULL)
1271 		return -ENOMEM;
1272 
1273 	if (copy_from_user(handles, user_handles,
1274 			   sizeof(uint32_t) * count_handles)) {
1275 		ret = -EFAULT;
1276 		goto err_free_handles;
1277 	}
1278 
1279 	syncobjs = kmalloc_array(count_handles, sizeof(*syncobjs), GFP_KERNEL);
1280 	if (syncobjs == NULL) {
1281 		ret = -ENOMEM;
1282 		goto err_free_handles;
1283 	}
1284 
1285 	for (i = 0; i < count_handles; i++) {
1286 		syncobjs[i] = drm_syncobj_find(file_private, handles[i]);
1287 		if (!syncobjs[i]) {
1288 			ret = -ENOENT;
1289 			goto err_put_syncobjs;
1290 		}
1291 	}
1292 
1293 	kfree(handles);
1294 	*syncobjs_out = syncobjs;
1295 	return 0;
1296 
1297 err_put_syncobjs:
1298 	while (i-- > 0)
1299 		drm_syncobj_put(syncobjs[i]);
1300 	kfree(syncobjs);
1301 err_free_handles:
1302 	kfree(handles);
1303 
1304 	return ret;
1305 }
1306 
drm_syncobj_array_free(struct drm_syncobj ** syncobjs,uint32_t count)1307 static void drm_syncobj_array_free(struct drm_syncobj **syncobjs,
1308 				   uint32_t count)
1309 {
1310 	uint32_t i;
1311 
1312 	for (i = 0; i < count; i++)
1313 		drm_syncobj_put(syncobjs[i]);
1314 	kfree(syncobjs);
1315 }
1316 
1317 int
drm_syncobj_wait_ioctl(struct drm_device * dev,void * data,struct drm_file * file_private)1318 drm_syncobj_wait_ioctl(struct drm_device *dev, void *data,
1319 		       struct drm_file *file_private)
1320 {
1321 	struct drm_syncobj_wait *args = data;
1322 	struct drm_syncobj **syncobjs;
1323 	unsigned int possible_flags;
1324 	ktime_t t, *tp = NULL;
1325 	int ret = 0;
1326 
1327 	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
1328 		return -EOPNOTSUPP;
1329 
1330 	possible_flags = DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL |
1331 			 DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT |
1332 			 DRM_SYNCOBJ_WAIT_FLAGS_WAIT_DEADLINE;
1333 
1334 	if (args->flags & ~possible_flags)
1335 		return -EINVAL;
1336 
1337 	if (args->count_handles == 0)
1338 		return 0;
1339 
1340 	ret = drm_syncobj_array_find(file_private,
1341 				     u64_to_user_ptr(args->handles),
1342 				     args->count_handles,
1343 				     &syncobjs);
1344 	if (ret < 0)
1345 		return ret;
1346 
1347 	if (args->flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_DEADLINE) {
1348 		t = ns_to_ktime(args->deadline_nsec);
1349 		tp = &t;
1350 	}
1351 
1352 	ret = drm_syncobj_array_wait(dev, file_private,
1353 				     args, NULL, syncobjs, false, tp);
1354 
1355 	drm_syncobj_array_free(syncobjs, args->count_handles);
1356 
1357 	return ret;
1358 }
1359 
1360 int
drm_syncobj_timeline_wait_ioctl(struct drm_device * dev,void * data,struct drm_file * file_private)1361 drm_syncobj_timeline_wait_ioctl(struct drm_device *dev, void *data,
1362 				struct drm_file *file_private)
1363 {
1364 	struct drm_syncobj_timeline_wait *args = data;
1365 	struct drm_syncobj **syncobjs;
1366 	unsigned int possible_flags;
1367 	ktime_t t, *tp = NULL;
1368 	int ret = 0;
1369 
1370 	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ_TIMELINE))
1371 		return -EOPNOTSUPP;
1372 
1373 	possible_flags = DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL |
1374 			 DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT |
1375 			 DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE |
1376 			 DRM_SYNCOBJ_WAIT_FLAGS_WAIT_DEADLINE;
1377 
1378 	if (args->flags & ~possible_flags)
1379 		return -EINVAL;
1380 
1381 	if (args->count_handles == 0)
1382 		return 0;
1383 
1384 	ret = drm_syncobj_array_find(file_private,
1385 				     u64_to_user_ptr(args->handles),
1386 				     args->count_handles,
1387 				     &syncobjs);
1388 	if (ret < 0)
1389 		return ret;
1390 
1391 	if (args->flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_DEADLINE) {
1392 		t = ns_to_ktime(args->deadline_nsec);
1393 		tp = &t;
1394 	}
1395 
1396 	ret = drm_syncobj_array_wait(dev, file_private,
1397 				     NULL, args, syncobjs, true, tp);
1398 
1399 	drm_syncobj_array_free(syncobjs, args->count_handles);
1400 
1401 	return ret;
1402 }
1403 
syncobj_eventfd_entry_fence_func(struct dma_fence * fence,struct dma_fence_cb * cb)1404 static void syncobj_eventfd_entry_fence_func(struct dma_fence *fence,
1405 					     struct dma_fence_cb *cb)
1406 {
1407 	struct syncobj_eventfd_entry *entry =
1408 		container_of(cb, struct syncobj_eventfd_entry, fence_cb);
1409 
1410 	eventfd_signal(entry->ev_fd_ctx);
1411 	syncobj_eventfd_entry_free(entry);
1412 }
1413 
1414 static void
syncobj_eventfd_entry_func(struct drm_syncobj * syncobj,struct syncobj_eventfd_entry * entry)1415 syncobj_eventfd_entry_func(struct drm_syncobj *syncobj,
1416 			   struct syncobj_eventfd_entry *entry)
1417 {
1418 	int ret;
1419 	struct dma_fence *fence;
1420 
1421 	/* This happens inside the syncobj lock */
1422 	fence = dma_fence_get(rcu_dereference_protected(syncobj->fence, 1));
1423 	if (!fence)
1424 		return;
1425 
1426 	ret = dma_fence_chain_find_seqno(&fence, entry->point);
1427 	if (ret != 0) {
1428 		/* The given seqno has not been submitted yet. */
1429 		dma_fence_put(fence);
1430 		return;
1431 	} else if (!fence) {
1432 		/* If dma_fence_chain_find_seqno returns 0 but sets the fence
1433 		 * to NULL, it implies that the given seqno is signaled and a
1434 		 * later seqno has already been submitted. Assign a stub fence
1435 		 * so that the eventfd still gets signaled below.
1436 		 */
1437 		fence = dma_fence_get_stub();
1438 	}
1439 
1440 	list_del_init(&entry->node);
1441 	entry->fence = fence;
1442 
1443 	if (entry->flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE) {
1444 		eventfd_signal(entry->ev_fd_ctx);
1445 		syncobj_eventfd_entry_free(entry);
1446 	} else {
1447 		ret = dma_fence_add_callback(fence, &entry->fence_cb,
1448 					     syncobj_eventfd_entry_fence_func);
1449 		if (ret == -ENOENT) {
1450 			eventfd_signal(entry->ev_fd_ctx);
1451 			syncobj_eventfd_entry_free(entry);
1452 		}
1453 	}
1454 }
1455 
1456 int
drm_syncobj_eventfd_ioctl(struct drm_device * dev,void * data,struct drm_file * file_private)1457 drm_syncobj_eventfd_ioctl(struct drm_device *dev, void *data,
1458 			  struct drm_file *file_private)
1459 {
1460 	struct drm_syncobj_eventfd *args = data;
1461 	struct drm_syncobj *syncobj;
1462 	struct eventfd_ctx *ev_fd_ctx;
1463 	struct syncobj_eventfd_entry *entry;
1464 	int ret;
1465 
1466 	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ_TIMELINE))
1467 		return -EOPNOTSUPP;
1468 
1469 	if (args->flags & ~DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE)
1470 		return -EINVAL;
1471 
1472 	if (args->pad)
1473 		return -EINVAL;
1474 
1475 	syncobj = drm_syncobj_find(file_private, args->handle);
1476 	if (!syncobj)
1477 		return -ENOENT;
1478 
1479 	ev_fd_ctx = eventfd_ctx_fdget(args->fd);
1480 	if (IS_ERR(ev_fd_ctx)) {
1481 		ret = PTR_ERR(ev_fd_ctx);
1482 		goto err_fdget;
1483 	}
1484 
1485 	entry = kzalloc(sizeof(*entry), GFP_KERNEL);
1486 	if (!entry) {
1487 		ret = -ENOMEM;
1488 		goto err_kzalloc;
1489 	}
1490 	entry->syncobj = syncobj;
1491 	entry->ev_fd_ctx = ev_fd_ctx;
1492 	entry->point = args->point;
1493 	entry->flags = args->flags;
1494 
1495 	drm_syncobj_add_eventfd(syncobj, entry);
1496 	drm_syncobj_put(syncobj);
1497 
1498 	return 0;
1499 
1500 err_kzalloc:
1501 	eventfd_ctx_put(ev_fd_ctx);
1502 err_fdget:
1503 	drm_syncobj_put(syncobj);
1504 	return ret;
1505 }
1506 
1507 int
drm_syncobj_reset_ioctl(struct drm_device * dev,void * data,struct drm_file * file_private)1508 drm_syncobj_reset_ioctl(struct drm_device *dev, void *data,
1509 			struct drm_file *file_private)
1510 {
1511 	struct drm_syncobj_array *args = data;
1512 	struct drm_syncobj **syncobjs;
1513 	uint32_t i;
1514 	int ret;
1515 
1516 	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
1517 		return -EOPNOTSUPP;
1518 
1519 	if (args->pad != 0)
1520 		return -EINVAL;
1521 
1522 	if (args->count_handles == 0)
1523 		return -EINVAL;
1524 
1525 	ret = drm_syncobj_array_find(file_private,
1526 				     u64_to_user_ptr(args->handles),
1527 				     args->count_handles,
1528 				     &syncobjs);
1529 	if (ret < 0)
1530 		return ret;
1531 
1532 	for (i = 0; i < args->count_handles; i++)
1533 		drm_syncobj_replace_fence(syncobjs[i], NULL);
1534 
1535 	drm_syncobj_array_free(syncobjs, args->count_handles);
1536 
1537 	return 0;
1538 }
1539 
1540 int
drm_syncobj_signal_ioctl(struct drm_device * dev,void * data,struct drm_file * file_private)1541 drm_syncobj_signal_ioctl(struct drm_device *dev, void *data,
1542 			 struct drm_file *file_private)
1543 {
1544 	struct drm_syncobj_array *args = data;
1545 	struct drm_syncobj **syncobjs;
1546 	uint32_t i;
1547 	int ret;
1548 
1549 	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
1550 		return -EOPNOTSUPP;
1551 
1552 	if (args->pad != 0)
1553 		return -EINVAL;
1554 
1555 	if (args->count_handles == 0)
1556 		return -EINVAL;
1557 
1558 	ret = drm_syncobj_array_find(file_private,
1559 				     u64_to_user_ptr(args->handles),
1560 				     args->count_handles,
1561 				     &syncobjs);
1562 	if (ret < 0)
1563 		return ret;
1564 
1565 	for (i = 0; i < args->count_handles; i++) {
1566 		ret = drm_syncobj_assign_null_handle(syncobjs[i]);
1567 		if (ret < 0)
1568 			break;
1569 	}
1570 
1571 	drm_syncobj_array_free(syncobjs, args->count_handles);
1572 
1573 	return ret;
1574 }
1575 
1576 int
drm_syncobj_timeline_signal_ioctl(struct drm_device * dev,void * data,struct drm_file * file_private)1577 drm_syncobj_timeline_signal_ioctl(struct drm_device *dev, void *data,
1578 				  struct drm_file *file_private)
1579 {
1580 	struct drm_syncobj_timeline_array *args = data;
1581 	struct drm_syncobj **syncobjs;
1582 	struct dma_fence_chain **chains;
1583 	uint64_t *points;
1584 	uint32_t i, j;
1585 	int ret;
1586 
1587 	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ_TIMELINE))
1588 		return -EOPNOTSUPP;
1589 
1590 	if (args->flags != 0)
1591 		return -EINVAL;
1592 
1593 	if (args->count_handles == 0)
1594 		return -EINVAL;
1595 
1596 	ret = drm_syncobj_array_find(file_private,
1597 				     u64_to_user_ptr(args->handles),
1598 				     args->count_handles,
1599 				     &syncobjs);
1600 	if (ret < 0)
1601 		return ret;
1602 
1603 	points = kmalloc_array(args->count_handles, sizeof(*points),
1604 			       GFP_KERNEL);
1605 	if (!points) {
1606 		ret = -ENOMEM;
1607 		goto out;
1608 	}
1609 	if (!u64_to_user_ptr(args->points)) {
1610 		memset(points, 0, args->count_handles * sizeof(uint64_t));
1611 	} else if (copy_from_user(points, u64_to_user_ptr(args->points),
1612 				  sizeof(uint64_t) * args->count_handles)) {
1613 		ret = -EFAULT;
1614 		goto err_points;
1615 	}
1616 
1617 	chains = kmalloc_array(args->count_handles, sizeof(void *), GFP_KERNEL);
1618 	if (!chains) {
1619 		ret = -ENOMEM;
1620 		goto err_points;
1621 	}
1622 	for (i = 0; i < args->count_handles; i++) {
1623 		chains[i] = dma_fence_chain_alloc();
1624 		if (!chains[i]) {
1625 			for (j = 0; j < i; j++)
1626 				dma_fence_chain_free(chains[j]);
1627 			ret = -ENOMEM;
1628 			goto err_chains;
1629 		}
1630 	}
1631 
1632 	for (i = 0; i < args->count_handles; i++) {
1633 		struct dma_fence *fence = dma_fence_get_stub();
1634 
1635 		drm_syncobj_add_point(syncobjs[i], chains[i],
1636 				      fence, points[i]);
1637 		dma_fence_put(fence);
1638 	}
1639 err_chains:
1640 	kfree(chains);
1641 err_points:
1642 	kfree(points);
1643 out:
1644 	drm_syncobj_array_free(syncobjs, args->count_handles);
1645 
1646 	return ret;
1647 }
1648 
drm_syncobj_query_ioctl(struct drm_device * dev,void * data,struct drm_file * file_private)1649 int drm_syncobj_query_ioctl(struct drm_device *dev, void *data,
1650 			    struct drm_file *file_private)
1651 {
1652 	struct drm_syncobj_timeline_array *args = data;
1653 	struct drm_syncobj **syncobjs;
1654 	uint64_t __user *points = u64_to_user_ptr(args->points);
1655 	uint32_t i;
1656 	int ret;
1657 
1658 	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ_TIMELINE))
1659 		return -EOPNOTSUPP;
1660 
1661 	if (args->flags & ~DRM_SYNCOBJ_QUERY_FLAGS_LAST_SUBMITTED)
1662 		return -EINVAL;
1663 
1664 	if (args->count_handles == 0)
1665 		return -EINVAL;
1666 
1667 	ret = drm_syncobj_array_find(file_private,
1668 				     u64_to_user_ptr(args->handles),
1669 				     args->count_handles,
1670 				     &syncobjs);
1671 	if (ret < 0)
1672 		return ret;
1673 
1674 	for (i = 0; i < args->count_handles; i++) {
1675 		struct dma_fence_chain *chain;
1676 		struct dma_fence *fence;
1677 		uint64_t point;
1678 
1679 		fence = drm_syncobj_fence_get(syncobjs[i]);
1680 		chain = to_dma_fence_chain(fence);
1681 		if (chain) {
1682 			struct dma_fence *iter, *last_signaled =
1683 				dma_fence_get(fence);
1684 
1685 			if (args->flags &
1686 			    DRM_SYNCOBJ_QUERY_FLAGS_LAST_SUBMITTED) {
1687 				point = fence->seqno;
1688 			} else {
1689 				dma_fence_chain_for_each(iter, fence) {
1690 					if (iter->context != fence->context) {
1691 						dma_fence_put(iter);
1692 						/* It is most likely that timeline has
1693 						* unorder points. */
1694 						break;
1695 					}
1696 					dma_fence_put(last_signaled);
1697 					last_signaled = dma_fence_get(iter);
1698 				}
1699 				point = dma_fence_is_signaled(last_signaled) ?
1700 					last_signaled->seqno :
1701 					to_dma_fence_chain(last_signaled)->prev_seqno;
1702 			}
1703 			dma_fence_put(last_signaled);
1704 		} else {
1705 			point = 0;
1706 		}
1707 		dma_fence_put(fence);
1708 		ret = copy_to_user(&points[i], &point, sizeof(uint64_t));
1709 		ret = ret ? -EFAULT : 0;
1710 		if (ret)
1711 			break;
1712 	}
1713 	drm_syncobj_array_free(syncobjs, args->count_handles);
1714 
1715 	return ret;
1716 }
1717