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 * Similarly, &DRM_IOCTL_SYNCOBJ_TIMELINE_WAIT takes an array of syncobj
130 * handles as well as an array of u64 points and does a host-side wait on all
131 * of syncobj fences at the given points simultaneously.
132 *
133 * &DRM_IOCTL_SYNCOBJ_TIMELINE_WAIT also adds the ability to wait for a given
134 * fence to materialize on the timeline without waiting for the fence to be
135 * signaled by using the &DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE flag. This
136 * requirement is inherited from the wait-before-signal behavior required by
137 * the Vulkan timeline semaphore API.
138 *
139 *
140 * Import/export of syncobjs
141 * -------------------------
142 *
143 * &DRM_IOCTL_SYNCOBJ_FD_TO_HANDLE and &DRM_IOCTL_SYNCOBJ_HANDLE_TO_FD
144 * provide two mechanisms for import/export of syncobjs.
145 *
146 * The first lets the client import or export an entire syncobj to a file
147 * descriptor.
148 * These fd's are opaque and have no other use case, except passing the
149 * syncobj between processes.
150 * All exported file descriptors and any syncobj handles created as a
151 * result of importing those file descriptors own a reference to the
152 * same underlying struct &drm_syncobj and the syncobj can be used
153 * persistently across all the processes with which it is shared.
154 * The syncobj is freed only once the last reference is dropped.
155 * Unlike dma-buf, importing a syncobj creates a new handle (with its own
156 * reference) for every import instead of de-duplicating.
157 * The primary use-case of this persistent import/export is for shared
158 * Vulkan fences and semaphores.
159 *
160 * The second import/export mechanism, which is indicated by
161 * &DRM_SYNCOBJ_FD_TO_HANDLE_FLAGS_IMPORT_SYNC_FILE or
162 * &DRM_SYNCOBJ_HANDLE_TO_FD_FLAGS_EXPORT_SYNC_FILE lets the client
163 * import/export the syncobj's current fence from/to a &sync_file.
164 * When a syncobj is exported to a sync file, that sync file wraps the
165 * sycnobj's fence at the time of export and any later signal or reset
166 * operations on the syncobj will not affect the exported sync file.
167 * When a sync file is imported into a syncobj, the syncobj's fence is set
168 * to the fence wrapped by that sync file.
169 * Because sync files are immutable, resetting or signaling the syncobj
170 * will not affect any sync files whose fences have been imported into the
171 * syncobj.
172 *
173 *
174 * Import/export of timeline points in timeline syncobjs
175 * -----------------------------------------------------
176 *
177 * &DRM_IOCTL_SYNCOBJ_TRANSFER provides a mechanism to transfer a struct
178 * &dma_fence_chain of a syncobj at a given u64 point to another u64 point
179 * into another syncobj.
180 *
181 * Note that if you want to transfer a struct &dma_fence_chain from a given
182 * point on a timeline syncobj from/into a binary syncobj, you can use the
183 * point 0 to mean take/replace the fence in the syncobj.
184 */
185
186#include <linux/anon_inodes.h>
187#include <linux/file.h>
188#include <linux/fs.h>
189#include <linux/sched/signal.h>
190#include <linux/sync_file.h>
191#include <linux/uaccess.h>
192
193#include <drm/drm.h>
194#include <drm/drm_drv.h>
195#include <drm/drm_file.h>
196#include <drm/drm_gem.h>
197#include <drm/drm_print.h>
198#include <drm/drm_syncobj.h>
199#include <drm/drm_utils.h>
200
201#include "drm_internal.h"
202
203struct syncobj_wait_entry {
204	struct list_head node;
205	struct task_struct *task;
206	struct dma_fence *fence;
207	struct dma_fence_cb fence_cb;
208	u64    point;
209};
210
211static void syncobj_wait_syncobj_func(struct drm_syncobj *syncobj,
212				      struct syncobj_wait_entry *wait);
213
214/**
215 * drm_syncobj_find - lookup and reference a sync object.
216 * @file_private: drm file private pointer
217 * @handle: sync object handle to lookup.
218 *
219 * Returns a reference to the syncobj pointed to by handle or NULL. The
220 * reference must be released by calling drm_syncobj_put().
221 */
222struct drm_syncobj *drm_syncobj_find(struct drm_file *file_private,
223				     u32 handle)
224{
225	struct drm_syncobj *syncobj;
226
227	spin_lock(&file_private->syncobj_table_lock);
228
229	/* Check if we currently have a reference on the object */
230	syncobj = idr_find(&file_private->syncobj_idr, handle);
231	if (syncobj)
232		drm_syncobj_get(syncobj);
233
234	spin_unlock(&file_private->syncobj_table_lock);
235
236	return syncobj;
237}
238EXPORT_SYMBOL(drm_syncobj_find);
239
240static void drm_syncobj_fence_add_wait(struct drm_syncobj *syncobj,
241				       struct syncobj_wait_entry *wait)
242{
243	struct dma_fence *fence;
244
245	if (wait->fence)
246		return;
247
248	spin_lock(&syncobj->lock);
249	/* We've already tried once to get a fence and failed.  Now that we
250	 * have the lock, try one more time just to be sure we don't add a
251	 * callback when a fence has already been set.
252	 */
253	fence = dma_fence_get(rcu_dereference_protected(syncobj->fence, 1));
254	if (!fence || dma_fence_chain_find_seqno(&fence, wait->point)) {
255		dma_fence_put(fence);
256		list_add_tail(&wait->node, &syncobj->cb_list);
257	} else if (!fence) {
258		wait->fence = dma_fence_get_stub();
259	} else {
260		wait->fence = fence;
261	}
262	spin_unlock(&syncobj->lock);
263}
264
265static void drm_syncobj_remove_wait(struct drm_syncobj *syncobj,
266				    struct syncobj_wait_entry *wait)
267{
268	if (!wait->node.next)
269		return;
270
271	spin_lock(&syncobj->lock);
272	list_del_init(&wait->node);
273	spin_unlock(&syncobj->lock);
274}
275
276/**
277 * drm_syncobj_add_point - add new timeline point to the syncobj
278 * @syncobj: sync object to add timeline point do
279 * @chain: chain node to use to add the point
280 * @fence: fence to encapsulate in the chain node
281 * @point: sequence number to use for the point
282 *
283 * Add the chain node as new timeline point to the syncobj.
284 */
285void drm_syncobj_add_point(struct drm_syncobj *syncobj,
286			   struct dma_fence_chain *chain,
287			   struct dma_fence *fence,
288			   uint64_t point)
289{
290	struct syncobj_wait_entry *cur, *tmp;
291	struct dma_fence *prev;
292
293	dma_fence_get(fence);
294
295	spin_lock(&syncobj->lock);
296
297	prev = drm_syncobj_fence_get(syncobj);
298	/* You are adding an unorder point to timeline, which could cause payload returned from query_ioctl is 0! */
299	if (prev && prev->seqno >= point)
300		DRM_DEBUG("You are adding an unorder point to timeline!\n");
301	dma_fence_chain_init(chain, prev, fence, point);
302	rcu_assign_pointer(syncobj->fence, &chain->base);
303
304	list_for_each_entry_safe(cur, tmp, &syncobj->cb_list, node)
305		syncobj_wait_syncobj_func(syncobj, cur);
306	spin_unlock(&syncobj->lock);
307
308	/* Walk the chain once to trigger garbage collection */
309	dma_fence_chain_for_each(fence, prev);
310	dma_fence_put(prev);
311}
312EXPORT_SYMBOL(drm_syncobj_add_point);
313
314/**
315 * drm_syncobj_replace_fence - replace fence in a sync object.
316 * @syncobj: Sync object to replace fence in
317 * @fence: fence to install in sync file.
318 *
319 * This replaces the fence on a sync object.
320 */
321void drm_syncobj_replace_fence(struct drm_syncobj *syncobj,
322			       struct dma_fence *fence)
323{
324	struct dma_fence *old_fence;
325	struct syncobj_wait_entry *cur, *tmp;
326
327	if (fence)
328		dma_fence_get(fence);
329
330	spin_lock(&syncobj->lock);
331
332	old_fence = rcu_dereference_protected(syncobj->fence,
333					      lockdep_is_held(&syncobj->lock));
334	rcu_assign_pointer(syncobj->fence, fence);
335
336	if (fence != old_fence) {
337		list_for_each_entry_safe(cur, tmp, &syncobj->cb_list, node)
338			syncobj_wait_syncobj_func(syncobj, cur);
339	}
340
341	spin_unlock(&syncobj->lock);
342
343	dma_fence_put(old_fence);
344}
345EXPORT_SYMBOL(drm_syncobj_replace_fence);
346
347/**
348 * drm_syncobj_assign_null_handle - assign a stub fence to the sync object
349 * @syncobj: sync object to assign the fence on
350 *
351 * Assign a already signaled stub fence to the sync object.
352 */
353static void drm_syncobj_assign_null_handle(struct drm_syncobj *syncobj)
354{
355	struct dma_fence *fence = dma_fence_get_stub();
356
357	drm_syncobj_replace_fence(syncobj, fence);
358	dma_fence_put(fence);
359}
360
361/* 5s default for wait submission */
362#define DRM_SYNCOBJ_WAIT_FOR_SUBMIT_TIMEOUT 5000000000ULL
363/**
364 * drm_syncobj_find_fence - lookup and reference the fence in a sync object
365 * @file_private: drm file private pointer
366 * @handle: sync object handle to lookup.
367 * @point: timeline point
368 * @flags: DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT or not
369 * @fence: out parameter for the fence
370 *
371 * This is just a convenience function that combines drm_syncobj_find() and
372 * drm_syncobj_fence_get().
373 *
374 * Returns 0 on success or a negative error value on failure. On success @fence
375 * contains a reference to the fence, which must be released by calling
376 * dma_fence_put().
377 */
378int drm_syncobj_find_fence(struct drm_file *file_private,
379			   u32 handle, u64 point, u64 flags,
380			   struct dma_fence **fence)
381{
382	struct drm_syncobj *syncobj = drm_syncobj_find(file_private, handle);
383	struct syncobj_wait_entry wait;
384	u64 timeout = nsecs_to_jiffies64(DRM_SYNCOBJ_WAIT_FOR_SUBMIT_TIMEOUT);
385	int ret;
386
387	if (!syncobj)
388		return -ENOENT;
389
390	*fence = drm_syncobj_fence_get(syncobj);
391
392	if (*fence) {
393		ret = dma_fence_chain_find_seqno(fence, point);
394		if (!ret) {
395			/* If the requested seqno is already signaled
396			 * drm_syncobj_find_fence may return a NULL
397			 * fence. To make sure the recipient gets
398			 * signalled, use a new fence instead.
399			 */
400			if (!*fence)
401				*fence = dma_fence_get_stub();
402
403			goto out;
404		}
405		dma_fence_put(*fence);
406	} else {
407		ret = -EINVAL;
408	}
409
410	if (!(flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT))
411		goto out;
412
413	memset(&wait, 0, sizeof(wait));
414	wait.task = current;
415	wait.point = point;
416	drm_syncobj_fence_add_wait(syncobj, &wait);
417
418	do {
419		set_current_state(TASK_INTERRUPTIBLE);
420		if (wait.fence) {
421			ret = 0;
422			break;
423		}
424                if (timeout == 0) {
425                        ret = -ETIME;
426                        break;
427                }
428
429		if (signal_pending(current)) {
430			ret = -ERESTARTSYS;
431			break;
432		}
433
434                timeout = schedule_timeout(timeout);
435	} while (1);
436
437	__set_current_state(TASK_RUNNING);
438	*fence = wait.fence;
439
440	if (wait.node.next)
441		drm_syncobj_remove_wait(syncobj, &wait);
442
443out:
444	drm_syncobj_put(syncobj);
445
446	return ret;
447}
448EXPORT_SYMBOL(drm_syncobj_find_fence);
449
450/**
451 * drm_syncobj_free - free a sync object.
452 * @kref: kref to free.
453 *
454 * Only to be called from kref_put in drm_syncobj_put.
455 */
456void drm_syncobj_free(struct kref *kref)
457{
458	struct drm_syncobj *syncobj = container_of(kref,
459						   struct drm_syncobj,
460						   refcount);
461	drm_syncobj_replace_fence(syncobj, NULL);
462	kfree(syncobj);
463}
464EXPORT_SYMBOL(drm_syncobj_free);
465
466/**
467 * drm_syncobj_create - create a new syncobj
468 * @out_syncobj: returned syncobj
469 * @flags: DRM_SYNCOBJ_* flags
470 * @fence: if non-NULL, the syncobj will represent this fence
471 *
472 * This is the first function to create a sync object. After creating, drivers
473 * probably want to make it available to userspace, either through
474 * drm_syncobj_get_handle() or drm_syncobj_get_fd().
475 *
476 * Returns 0 on success or a negative error value on failure.
477 */
478int drm_syncobj_create(struct drm_syncobj **out_syncobj, uint32_t flags,
479		       struct dma_fence *fence)
480{
481	struct drm_syncobj *syncobj;
482
483	syncobj = kzalloc(sizeof(struct drm_syncobj), GFP_KERNEL);
484	if (!syncobj)
485		return -ENOMEM;
486
487	kref_init(&syncobj->refcount);
488	INIT_LIST_HEAD(&syncobj->cb_list);
489	spin_lock_init(&syncobj->lock);
490
491	if (flags & DRM_SYNCOBJ_CREATE_SIGNALED)
492		drm_syncobj_assign_null_handle(syncobj);
493
494	if (fence)
495		drm_syncobj_replace_fence(syncobj, fence);
496
497	*out_syncobj = syncobj;
498	return 0;
499}
500EXPORT_SYMBOL(drm_syncobj_create);
501
502/**
503 * drm_syncobj_get_handle - get a handle from a syncobj
504 * @file_private: drm file private pointer
505 * @syncobj: Sync object to export
506 * @handle: out parameter with the new handle
507 *
508 * Exports a sync object created with drm_syncobj_create() as a handle on
509 * @file_private to userspace.
510 *
511 * Returns 0 on success or a negative error value on failure.
512 */
513int drm_syncobj_get_handle(struct drm_file *file_private,
514			   struct drm_syncobj *syncobj, u32 *handle)
515{
516	int ret;
517
518	/* take a reference to put in the idr */
519	drm_syncobj_get(syncobj);
520
521	idr_preload(GFP_KERNEL);
522	spin_lock(&file_private->syncobj_table_lock);
523	ret = idr_alloc(&file_private->syncobj_idr, syncobj, 1, 0, GFP_NOWAIT);
524	spin_unlock(&file_private->syncobj_table_lock);
525
526	idr_preload_end();
527
528	if (ret < 0) {
529		drm_syncobj_put(syncobj);
530		return ret;
531	}
532
533	*handle = ret;
534	return 0;
535}
536EXPORT_SYMBOL(drm_syncobj_get_handle);
537
538static int drm_syncobj_create_as_handle(struct drm_file *file_private,
539					u32 *handle, uint32_t flags)
540{
541	int ret;
542	struct drm_syncobj *syncobj;
543
544	ret = drm_syncobj_create(&syncobj, flags, NULL);
545	if (ret)
546		return ret;
547
548	ret = drm_syncobj_get_handle(file_private, syncobj, handle);
549	drm_syncobj_put(syncobj);
550	return ret;
551}
552
553static int drm_syncobj_destroy(struct drm_file *file_private,
554			       u32 handle)
555{
556	struct drm_syncobj *syncobj;
557
558	spin_lock(&file_private->syncobj_table_lock);
559	syncobj = idr_remove(&file_private->syncobj_idr, handle);
560	spin_unlock(&file_private->syncobj_table_lock);
561
562	if (!syncobj)
563		return -EINVAL;
564
565	drm_syncobj_put(syncobj);
566	return 0;
567}
568
569static int drm_syncobj_file_release(struct inode *inode, struct file *file)
570{
571	struct drm_syncobj *syncobj = file->private_data;
572
573	drm_syncobj_put(syncobj);
574	return 0;
575}
576
577static const struct file_operations drm_syncobj_file_fops = {
578	.release = drm_syncobj_file_release,
579};
580
581/**
582 * drm_syncobj_get_fd - get a file descriptor from a syncobj
583 * @syncobj: Sync object to export
584 * @p_fd: out parameter with the new file descriptor
585 *
586 * Exports a sync object created with drm_syncobj_create() as a file descriptor.
587 *
588 * Returns 0 on success or a negative error value on failure.
589 */
590int drm_syncobj_get_fd(struct drm_syncobj *syncobj, int *p_fd)
591{
592	struct file *file;
593	int fd;
594
595	fd = get_unused_fd_flags(O_CLOEXEC);
596	if (fd < 0)
597		return fd;
598
599	file = anon_inode_getfile("syncobj_file",
600				  &drm_syncobj_file_fops,
601				  syncobj, 0);
602	if (IS_ERR(file)) {
603		put_unused_fd(fd);
604		return PTR_ERR(file);
605	}
606
607	drm_syncobj_get(syncobj);
608	fd_install(fd, file);
609
610	*p_fd = fd;
611	return 0;
612}
613EXPORT_SYMBOL(drm_syncobj_get_fd);
614
615static int drm_syncobj_handle_to_fd(struct drm_file *file_private,
616				    u32 handle, int *p_fd)
617{
618	struct drm_syncobj *syncobj = drm_syncobj_find(file_private, handle);
619	int ret;
620
621	if (!syncobj)
622		return -EINVAL;
623
624	ret = drm_syncobj_get_fd(syncobj, p_fd);
625	drm_syncobj_put(syncobj);
626	return ret;
627}
628
629static int drm_syncobj_fd_to_handle(struct drm_file *file_private,
630				    int fd, u32 *handle)
631{
632	struct drm_syncobj *syncobj;
633	struct fd f = fdget(fd);
634	int ret;
635
636	if (!f.file)
637		return -EINVAL;
638
639	if (f.file->f_op != &drm_syncobj_file_fops) {
640		fdput(f);
641		return -EINVAL;
642	}
643
644	/* take a reference to put in the idr */
645	syncobj = f.file->private_data;
646	drm_syncobj_get(syncobj);
647
648	idr_preload(GFP_KERNEL);
649	spin_lock(&file_private->syncobj_table_lock);
650	ret = idr_alloc(&file_private->syncobj_idr, syncobj, 1, 0, GFP_NOWAIT);
651	spin_unlock(&file_private->syncobj_table_lock);
652	idr_preload_end();
653
654	if (ret > 0) {
655		*handle = ret;
656		ret = 0;
657	} else
658		drm_syncobj_put(syncobj);
659
660	fdput(f);
661	return ret;
662}
663
664static int drm_syncobj_import_sync_file_fence(struct drm_file *file_private,
665					      int fd, int handle)
666{
667	struct dma_fence *fence = sync_file_get_fence(fd);
668	struct drm_syncobj *syncobj;
669
670	if (!fence)
671		return -EINVAL;
672
673	syncobj = drm_syncobj_find(file_private, handle);
674	if (!syncobj) {
675		dma_fence_put(fence);
676		return -ENOENT;
677	}
678
679	drm_syncobj_replace_fence(syncobj, fence);
680	dma_fence_put(fence);
681	drm_syncobj_put(syncobj);
682	return 0;
683}
684
685static int drm_syncobj_export_sync_file(struct drm_file *file_private,
686					int handle, int *p_fd)
687{
688	int ret;
689	struct dma_fence *fence;
690	struct sync_file *sync_file;
691	int fd = get_unused_fd_flags(O_CLOEXEC);
692
693	if (fd < 0)
694		return fd;
695
696	ret = drm_syncobj_find_fence(file_private, handle, 0, 0, &fence);
697	if (ret)
698		goto err_put_fd;
699
700	sync_file = sync_file_create(fence);
701
702	dma_fence_put(fence);
703
704	if (!sync_file) {
705		ret = -EINVAL;
706		goto err_put_fd;
707	}
708
709	fd_install(fd, sync_file->file);
710
711	*p_fd = fd;
712	return 0;
713err_put_fd:
714	put_unused_fd(fd);
715	return ret;
716}
717/**
718 * drm_syncobj_open - initalizes syncobj file-private structures at devnode open time
719 * @file_private: drm file-private structure to set up
720 *
721 * Called at device open time, sets up the structure for handling refcounting
722 * of sync objects.
723 */
724void
725drm_syncobj_open(struct drm_file *file_private)
726{
727	idr_init_base(&file_private->syncobj_idr, 1);
728	spin_lock_init(&file_private->syncobj_table_lock);
729}
730
731static int
732drm_syncobj_release_handle(int id, void *ptr, void *data)
733{
734	struct drm_syncobj *syncobj = ptr;
735
736	drm_syncobj_put(syncobj);
737	return 0;
738}
739
740/**
741 * drm_syncobj_release - release file-private sync object resources
742 * @file_private: drm file-private structure to clean up
743 *
744 * Called at close time when the filp is going away.
745 *
746 * Releases any remaining references on objects by this filp.
747 */
748void
749drm_syncobj_release(struct drm_file *file_private)
750{
751	idr_for_each(&file_private->syncobj_idr,
752		     &drm_syncobj_release_handle, file_private);
753	idr_destroy(&file_private->syncobj_idr);
754}
755
756int
757drm_syncobj_create_ioctl(struct drm_device *dev, void *data,
758			 struct drm_file *file_private)
759{
760	struct drm_syncobj_create *args = data;
761
762	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
763		return -EOPNOTSUPP;
764
765	/* no valid flags yet */
766	if (args->flags & ~DRM_SYNCOBJ_CREATE_SIGNALED)
767		return -EINVAL;
768
769	return drm_syncobj_create_as_handle(file_private,
770					    &args->handle, args->flags);
771}
772
773int
774drm_syncobj_destroy_ioctl(struct drm_device *dev, void *data,
775			  struct drm_file *file_private)
776{
777	struct drm_syncobj_destroy *args = data;
778
779	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
780		return -EOPNOTSUPP;
781
782	/* make sure padding is empty */
783	if (args->pad)
784		return -EINVAL;
785	return drm_syncobj_destroy(file_private, args->handle);
786}
787
788int
789drm_syncobj_handle_to_fd_ioctl(struct drm_device *dev, void *data,
790				   struct drm_file *file_private)
791{
792	struct drm_syncobj_handle *args = data;
793
794	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
795		return -EOPNOTSUPP;
796
797	if (args->pad)
798		return -EINVAL;
799
800	if (args->flags != 0 &&
801	    args->flags != DRM_SYNCOBJ_HANDLE_TO_FD_FLAGS_EXPORT_SYNC_FILE)
802		return -EINVAL;
803
804	if (args->flags & DRM_SYNCOBJ_HANDLE_TO_FD_FLAGS_EXPORT_SYNC_FILE)
805		return drm_syncobj_export_sync_file(file_private, args->handle,
806						    &args->fd);
807
808	return drm_syncobj_handle_to_fd(file_private, args->handle,
809					&args->fd);
810}
811
812int
813drm_syncobj_fd_to_handle_ioctl(struct drm_device *dev, void *data,
814				   struct drm_file *file_private)
815{
816	struct drm_syncobj_handle *args = data;
817
818	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
819		return -EOPNOTSUPP;
820
821	if (args->pad)
822		return -EINVAL;
823
824	if (args->flags != 0 &&
825	    args->flags != DRM_SYNCOBJ_FD_TO_HANDLE_FLAGS_IMPORT_SYNC_FILE)
826		return -EINVAL;
827
828	if (args->flags & DRM_SYNCOBJ_FD_TO_HANDLE_FLAGS_IMPORT_SYNC_FILE)
829		return drm_syncobj_import_sync_file_fence(file_private,
830							  args->fd,
831							  args->handle);
832
833	return drm_syncobj_fd_to_handle(file_private, args->fd,
834					&args->handle);
835}
836
837static int drm_syncobj_transfer_to_timeline(struct drm_file *file_private,
838					    struct drm_syncobj_transfer *args)
839{
840	struct drm_syncobj *timeline_syncobj = NULL;
841	struct dma_fence *fence;
842	struct dma_fence_chain *chain;
843	int ret;
844
845	timeline_syncobj = drm_syncobj_find(file_private, args->dst_handle);
846	if (!timeline_syncobj) {
847		return -ENOENT;
848	}
849	ret = drm_syncobj_find_fence(file_private, args->src_handle,
850				     args->src_point, args->flags,
851				     &fence);
852	if (ret)
853		goto err;
854	chain = kzalloc(sizeof(struct dma_fence_chain), GFP_KERNEL);
855	if (!chain) {
856		ret = -ENOMEM;
857		goto err1;
858	}
859	drm_syncobj_add_point(timeline_syncobj, chain, fence, args->dst_point);
860err1:
861	dma_fence_put(fence);
862err:
863	drm_syncobj_put(timeline_syncobj);
864
865	return ret;
866}
867
868static int
869drm_syncobj_transfer_to_binary(struct drm_file *file_private,
870			       struct drm_syncobj_transfer *args)
871{
872	struct drm_syncobj *binary_syncobj = NULL;
873	struct dma_fence *fence;
874	int ret;
875
876	binary_syncobj = drm_syncobj_find(file_private, args->dst_handle);
877	if (!binary_syncobj)
878		return -ENOENT;
879	ret = drm_syncobj_find_fence(file_private, args->src_handle,
880				     args->src_point, args->flags, &fence);
881	if (ret)
882		goto err;
883	drm_syncobj_replace_fence(binary_syncobj, fence);
884	dma_fence_put(fence);
885err:
886	drm_syncobj_put(binary_syncobj);
887
888	return ret;
889}
890int
891drm_syncobj_transfer_ioctl(struct drm_device *dev, void *data,
892			   struct drm_file *file_private)
893{
894	struct drm_syncobj_transfer *args = data;
895	int ret;
896
897	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ_TIMELINE))
898		return -EOPNOTSUPP;
899
900	if (args->pad)
901		return -EINVAL;
902
903	if (args->dst_point)
904		ret = drm_syncobj_transfer_to_timeline(file_private, args);
905	else
906		ret = drm_syncobj_transfer_to_binary(file_private, args);
907
908	return ret;
909}
910
911static void syncobj_wait_fence_func(struct dma_fence *fence,
912				    struct dma_fence_cb *cb)
913{
914	struct syncobj_wait_entry *wait =
915		container_of(cb, struct syncobj_wait_entry, fence_cb);
916
917	wake_up_process(wait->task);
918}
919
920static void syncobj_wait_syncobj_func(struct drm_syncobj *syncobj,
921				      struct syncobj_wait_entry *wait)
922{
923	struct dma_fence *fence;
924
925	/* This happens inside the syncobj lock */
926	fence = rcu_dereference_protected(syncobj->fence,
927					  lockdep_is_held(&syncobj->lock));
928	dma_fence_get(fence);
929	if (!fence || dma_fence_chain_find_seqno(&fence, wait->point)) {
930		dma_fence_put(fence);
931		return;
932	} else if (!fence) {
933		wait->fence = dma_fence_get_stub();
934	} else {
935		wait->fence = fence;
936	}
937
938	wake_up_process(wait->task);
939	list_del_init(&wait->node);
940}
941
942static signed long drm_syncobj_array_wait_timeout(struct drm_syncobj **syncobjs,
943						  void __user *user_points,
944						  uint32_t count,
945						  uint32_t flags,
946						  signed long timeout,
947						  uint32_t *idx)
948{
949	struct syncobj_wait_entry *entries;
950	struct dma_fence *fence;
951	uint64_t *points;
952	uint32_t signaled_count, i;
953
954	points = kmalloc_array(count, sizeof(*points), GFP_KERNEL);
955	if (points == NULL)
956		return -ENOMEM;
957
958	if (!user_points) {
959		memset(points, 0, count * sizeof(uint64_t));
960
961	} else if (copy_from_user(points, user_points,
962				  sizeof(uint64_t) * count)) {
963		timeout = -EFAULT;
964		goto err_free_points;
965	}
966
967	entries = kcalloc(count, sizeof(*entries), GFP_KERNEL);
968	if (!entries) {
969		timeout = -ENOMEM;
970		goto err_free_points;
971	}
972	/* Walk the list of sync objects and initialize entries.  We do
973	 * this up-front so that we can properly return -EINVAL if there is
974	 * a syncobj with a missing fence and then never have the chance of
975	 * returning -EINVAL again.
976	 */
977	signaled_count = 0;
978	for (i = 0; i < count; ++i) {
979		struct dma_fence *fence;
980
981		entries[i].task = current;
982		entries[i].point = points[i];
983		fence = drm_syncobj_fence_get(syncobjs[i]);
984		if (!fence || dma_fence_chain_find_seqno(&fence, points[i])) {
985			dma_fence_put(fence);
986			if (flags & (DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT |
987				     DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE)) {
988				continue;
989			} else {
990				timeout = -EINVAL;
991				goto cleanup_entries;
992			}
993		}
994
995		if (fence)
996			entries[i].fence = fence;
997		else
998			entries[i].fence = dma_fence_get_stub();
999
1000		if ((flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE) ||
1001		    dma_fence_is_signaled(entries[i].fence)) {
1002			if (signaled_count == 0 && idx)
1003				*idx = i;
1004			signaled_count++;
1005		}
1006	}
1007
1008	if (signaled_count == count ||
1009	    (signaled_count > 0 &&
1010	     !(flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL)))
1011		goto cleanup_entries;
1012
1013	/* There's a very annoying laxness in the dma_fence API here, in
1014	 * that backends are not required to automatically report when a
1015	 * fence is signaled prior to fence->ops->enable_signaling() being
1016	 * called.  So here if we fail to match signaled_count, we need to
1017	 * fallthough and try a 0 timeout wait!
1018	 */
1019
1020	if (flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT) {
1021		for (i = 0; i < count; ++i)
1022			drm_syncobj_fence_add_wait(syncobjs[i], &entries[i]);
1023	}
1024
1025	do {
1026		set_current_state(TASK_INTERRUPTIBLE);
1027
1028		signaled_count = 0;
1029		for (i = 0; i < count; ++i) {
1030			fence = entries[i].fence;
1031			if (!fence)
1032				continue;
1033
1034			if ((flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE) ||
1035			    dma_fence_is_signaled(fence) ||
1036			    (!entries[i].fence_cb.func &&
1037			     dma_fence_add_callback(fence,
1038						    &entries[i].fence_cb,
1039						    syncobj_wait_fence_func))) {
1040				/* The fence has been signaled */
1041				if (flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL) {
1042					signaled_count++;
1043				} else {
1044					if (idx)
1045						*idx = i;
1046					goto done_waiting;
1047				}
1048			}
1049		}
1050
1051		if (signaled_count == count)
1052			goto done_waiting;
1053
1054		if (timeout == 0) {
1055			timeout = -ETIME;
1056			goto done_waiting;
1057		}
1058
1059		if (signal_pending(current)) {
1060			timeout = -ERESTARTSYS;
1061			goto done_waiting;
1062		}
1063
1064		timeout = schedule_timeout(timeout);
1065	} while (1);
1066
1067done_waiting:
1068	__set_current_state(TASK_RUNNING);
1069
1070cleanup_entries:
1071	for (i = 0; i < count; ++i) {
1072		drm_syncobj_remove_wait(syncobjs[i], &entries[i]);
1073		if (entries[i].fence_cb.func)
1074			dma_fence_remove_callback(entries[i].fence,
1075						  &entries[i].fence_cb);
1076		dma_fence_put(entries[i].fence);
1077	}
1078	kfree(entries);
1079
1080err_free_points:
1081	kfree(points);
1082
1083	return timeout;
1084}
1085
1086/**
1087 * drm_timeout_abs_to_jiffies - calculate jiffies timeout from absolute value
1088 *
1089 * @timeout_nsec: timeout nsec component in ns, 0 for poll
1090 *
1091 * Calculate the timeout in jiffies from an absolute time in sec/nsec.
1092 */
1093signed long drm_timeout_abs_to_jiffies(int64_t timeout_nsec)
1094{
1095	ktime_t abs_timeout, now;
1096	u64 timeout_ns, timeout_jiffies64;
1097
1098	/* make 0 timeout means poll - absolute 0 doesn't seem valid */
1099	if (timeout_nsec == 0)
1100		return 0;
1101
1102	abs_timeout = ns_to_ktime(timeout_nsec);
1103	now = ktime_get();
1104
1105	if (!ktime_after(abs_timeout, now))
1106		return 0;
1107
1108	timeout_ns = ktime_to_ns(ktime_sub(abs_timeout, now));
1109
1110	timeout_jiffies64 = nsecs_to_jiffies64(timeout_ns);
1111	/*  clamp timeout to avoid infinite timeout */
1112	if (timeout_jiffies64 >= MAX_SCHEDULE_TIMEOUT - 1)
1113		return MAX_SCHEDULE_TIMEOUT - 1;
1114
1115	return timeout_jiffies64 + 1;
1116}
1117EXPORT_SYMBOL(drm_timeout_abs_to_jiffies);
1118
1119static int drm_syncobj_array_wait(struct drm_device *dev,
1120				  struct drm_file *file_private,
1121				  struct drm_syncobj_wait *wait,
1122				  struct drm_syncobj_timeline_wait *timeline_wait,
1123				  struct drm_syncobj **syncobjs, bool timeline)
1124{
1125	signed long timeout = 0;
1126	uint32_t first = ~0;
1127
1128	if (!timeline) {
1129		timeout = drm_timeout_abs_to_jiffies(wait->timeout_nsec);
1130		timeout = drm_syncobj_array_wait_timeout(syncobjs,
1131							 NULL,
1132							 wait->count_handles,
1133							 wait->flags,
1134							 timeout, &first);
1135		if (timeout < 0)
1136			return timeout;
1137		wait->first_signaled = first;
1138	} else {
1139		timeout = drm_timeout_abs_to_jiffies(timeline_wait->timeout_nsec);
1140		timeout = drm_syncobj_array_wait_timeout(syncobjs,
1141							 u64_to_user_ptr(timeline_wait->points),
1142							 timeline_wait->count_handles,
1143							 timeline_wait->flags,
1144							 timeout, &first);
1145		if (timeout < 0)
1146			return timeout;
1147		timeline_wait->first_signaled = first;
1148	}
1149	return 0;
1150}
1151
1152static int drm_syncobj_array_find(struct drm_file *file_private,
1153				  void __user *user_handles,
1154				  uint32_t count_handles,
1155				  struct drm_syncobj ***syncobjs_out)
1156{
1157	uint32_t i, *handles;
1158	struct drm_syncobj **syncobjs;
1159	int ret;
1160
1161	handles = kmalloc_array(count_handles, sizeof(*handles), GFP_KERNEL);
1162	if (handles == NULL)
1163		return -ENOMEM;
1164
1165	if (copy_from_user(handles, user_handles,
1166			   sizeof(uint32_t) * count_handles)) {
1167		ret = -EFAULT;
1168		goto err_free_handles;
1169	}
1170
1171	syncobjs = kmalloc_array(count_handles, sizeof(*syncobjs), GFP_KERNEL);
1172	if (syncobjs == NULL) {
1173		ret = -ENOMEM;
1174		goto err_free_handles;
1175	}
1176
1177	for (i = 0; i < count_handles; i++) {
1178		syncobjs[i] = drm_syncobj_find(file_private, handles[i]);
1179		if (!syncobjs[i]) {
1180			ret = -ENOENT;
1181			goto err_put_syncobjs;
1182		}
1183	}
1184
1185	kfree(handles);
1186	*syncobjs_out = syncobjs;
1187	return 0;
1188
1189err_put_syncobjs:
1190	while (i-- > 0)
1191		drm_syncobj_put(syncobjs[i]);
1192	kfree(syncobjs);
1193err_free_handles:
1194	kfree(handles);
1195
1196	return ret;
1197}
1198
1199static void drm_syncobj_array_free(struct drm_syncobj **syncobjs,
1200				   uint32_t count)
1201{
1202	uint32_t i;
1203
1204	for (i = 0; i < count; i++)
1205		drm_syncobj_put(syncobjs[i]);
1206	kfree(syncobjs);
1207}
1208
1209int
1210drm_syncobj_wait_ioctl(struct drm_device *dev, void *data,
1211		       struct drm_file *file_private)
1212{
1213	struct drm_syncobj_wait *args = data;
1214	struct drm_syncobj **syncobjs;
1215	int ret = 0;
1216
1217	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
1218		return -EOPNOTSUPP;
1219
1220	if (args->flags & ~(DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL |
1221			    DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT))
1222		return -EINVAL;
1223
1224	if (args->count_handles == 0)
1225		return -EINVAL;
1226
1227	ret = drm_syncobj_array_find(file_private,
1228				     u64_to_user_ptr(args->handles),
1229				     args->count_handles,
1230				     &syncobjs);
1231	if (ret < 0)
1232		return ret;
1233
1234	ret = drm_syncobj_array_wait(dev, file_private,
1235				     args, NULL, syncobjs, false);
1236
1237	drm_syncobj_array_free(syncobjs, args->count_handles);
1238
1239	return ret;
1240}
1241
1242int
1243drm_syncobj_timeline_wait_ioctl(struct drm_device *dev, void *data,
1244				struct drm_file *file_private)
1245{
1246	struct drm_syncobj_timeline_wait *args = data;
1247	struct drm_syncobj **syncobjs;
1248	int ret = 0;
1249
1250	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ_TIMELINE))
1251		return -EOPNOTSUPP;
1252
1253	if (args->flags & ~(DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL |
1254			    DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT |
1255			    DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE))
1256		return -EINVAL;
1257
1258	if (args->count_handles == 0)
1259		return -EINVAL;
1260
1261	ret = drm_syncobj_array_find(file_private,
1262				     u64_to_user_ptr(args->handles),
1263				     args->count_handles,
1264				     &syncobjs);
1265	if (ret < 0)
1266		return ret;
1267
1268	ret = drm_syncobj_array_wait(dev, file_private,
1269				     NULL, args, syncobjs, true);
1270
1271	drm_syncobj_array_free(syncobjs, args->count_handles);
1272
1273	return ret;
1274}
1275
1276
1277int
1278drm_syncobj_reset_ioctl(struct drm_device *dev, void *data,
1279			struct drm_file *file_private)
1280{
1281	struct drm_syncobj_array *args = data;
1282	struct drm_syncobj **syncobjs;
1283	uint32_t i;
1284	int ret;
1285
1286	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
1287		return -EOPNOTSUPP;
1288
1289	if (args->pad != 0)
1290		return -EINVAL;
1291
1292	if (args->count_handles == 0)
1293		return -EINVAL;
1294
1295	ret = drm_syncobj_array_find(file_private,
1296				     u64_to_user_ptr(args->handles),
1297				     args->count_handles,
1298				     &syncobjs);
1299	if (ret < 0)
1300		return ret;
1301
1302	for (i = 0; i < args->count_handles; i++)
1303		drm_syncobj_replace_fence(syncobjs[i], NULL);
1304
1305	drm_syncobj_array_free(syncobjs, args->count_handles);
1306
1307	return 0;
1308}
1309
1310int
1311drm_syncobj_signal_ioctl(struct drm_device *dev, void *data,
1312			 struct drm_file *file_private)
1313{
1314	struct drm_syncobj_array *args = data;
1315	struct drm_syncobj **syncobjs;
1316	uint32_t i;
1317	int ret;
1318
1319	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
1320		return -EOPNOTSUPP;
1321
1322	if (args->pad != 0)
1323		return -EINVAL;
1324
1325	if (args->count_handles == 0)
1326		return -EINVAL;
1327
1328	ret = drm_syncobj_array_find(file_private,
1329				     u64_to_user_ptr(args->handles),
1330				     args->count_handles,
1331				     &syncobjs);
1332	if (ret < 0)
1333		return ret;
1334
1335	for (i = 0; i < args->count_handles; i++)
1336		drm_syncobj_assign_null_handle(syncobjs[i]);
1337
1338	drm_syncobj_array_free(syncobjs, args->count_handles);
1339
1340	return ret;
1341}
1342
1343int
1344drm_syncobj_timeline_signal_ioctl(struct drm_device *dev, void *data,
1345				  struct drm_file *file_private)
1346{
1347	struct drm_syncobj_timeline_array *args = data;
1348	struct drm_syncobj **syncobjs;
1349	struct dma_fence_chain **chains;
1350	uint64_t *points;
1351	uint32_t i, j;
1352	int ret;
1353
1354	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ_TIMELINE))
1355		return -EOPNOTSUPP;
1356
1357	if (args->flags != 0)
1358		return -EINVAL;
1359
1360	if (args->count_handles == 0)
1361		return -EINVAL;
1362
1363	ret = drm_syncobj_array_find(file_private,
1364				     u64_to_user_ptr(args->handles),
1365				     args->count_handles,
1366				     &syncobjs);
1367	if (ret < 0)
1368		return ret;
1369
1370	points = kmalloc_array(args->count_handles, sizeof(*points),
1371			       GFP_KERNEL);
1372	if (!points) {
1373		ret = -ENOMEM;
1374		goto out;
1375	}
1376	if (!u64_to_user_ptr(args->points)) {
1377		memset(points, 0, args->count_handles * sizeof(uint64_t));
1378	} else if (copy_from_user(points, u64_to_user_ptr(args->points),
1379				  sizeof(uint64_t) * args->count_handles)) {
1380		ret = -EFAULT;
1381		goto err_points;
1382	}
1383
1384	chains = kmalloc_array(args->count_handles, sizeof(void *), GFP_KERNEL);
1385	if (!chains) {
1386		ret = -ENOMEM;
1387		goto err_points;
1388	}
1389	for (i = 0; i < args->count_handles; i++) {
1390		chains[i] = kzalloc(sizeof(struct dma_fence_chain), GFP_KERNEL);
1391		if (!chains[i]) {
1392			for (j = 0; j < i; j++)
1393				kfree(chains[j]);
1394			ret = -ENOMEM;
1395			goto err_chains;
1396		}
1397	}
1398
1399	for (i = 0; i < args->count_handles; i++) {
1400		struct dma_fence *fence = dma_fence_get_stub();
1401
1402		drm_syncobj_add_point(syncobjs[i], chains[i],
1403				      fence, points[i]);
1404		dma_fence_put(fence);
1405	}
1406err_chains:
1407	kfree(chains);
1408err_points:
1409	kfree(points);
1410out:
1411	drm_syncobj_array_free(syncobjs, args->count_handles);
1412
1413	return ret;
1414}
1415
1416int drm_syncobj_query_ioctl(struct drm_device *dev, void *data,
1417			    struct drm_file *file_private)
1418{
1419	struct drm_syncobj_timeline_array *args = data;
1420	struct drm_syncobj **syncobjs;
1421	uint64_t __user *points = u64_to_user_ptr(args->points);
1422	uint32_t i;
1423	int ret;
1424
1425	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ_TIMELINE))
1426		return -EOPNOTSUPP;
1427
1428	if (args->flags & ~DRM_SYNCOBJ_QUERY_FLAGS_LAST_SUBMITTED)
1429		return -EINVAL;
1430
1431	if (args->count_handles == 0)
1432		return -EINVAL;
1433
1434	ret = drm_syncobj_array_find(file_private,
1435				     u64_to_user_ptr(args->handles),
1436				     args->count_handles,
1437				     &syncobjs);
1438	if (ret < 0)
1439		return ret;
1440
1441	for (i = 0; i < args->count_handles; i++) {
1442		struct dma_fence_chain *chain;
1443		struct dma_fence *fence;
1444		uint64_t point;
1445
1446		fence = drm_syncobj_fence_get(syncobjs[i]);
1447		chain = to_dma_fence_chain(fence);
1448		if (chain) {
1449			struct dma_fence *iter, *last_signaled =
1450				dma_fence_get(fence);
1451
1452			if (args->flags &
1453			    DRM_SYNCOBJ_QUERY_FLAGS_LAST_SUBMITTED) {
1454				point = fence->seqno;
1455			} else {
1456				dma_fence_chain_for_each(iter, fence) {
1457					if (iter->context != fence->context) {
1458						dma_fence_put(iter);
1459						/* It is most likely that timeline has
1460						* unorder points. */
1461						break;
1462					}
1463					dma_fence_put(last_signaled);
1464					last_signaled = dma_fence_get(iter);
1465				}
1466				point = dma_fence_is_signaled(last_signaled) ?
1467					last_signaled->seqno :
1468					to_dma_fence_chain(last_signaled)->prev_seqno;
1469			}
1470			dma_fence_put(last_signaled);
1471		} else {
1472			point = 0;
1473		}
1474		dma_fence_put(fence);
1475		ret = copy_to_user(&points[i], &point, sizeof(uint64_t));
1476		ret = ret ? -EFAULT : 0;
1477		if (ret)
1478			break;
1479	}
1480	drm_syncobj_array_free(syncobjs, args->count_handles);
1481
1482	return ret;
1483}
1484