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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) are a persistent objects,
33  * that contain an optional fence. The fence can be updated with a new
34  * fence, or be NULL.
35  *
36  * syncobj's can be waited upon, where it will wait for the underlying
37  * fence.
38  *
39  * syncobj's can be export to fd's and back, these fd's are opaque and
40  * have no other use case, except passing the syncobj between processes.
41  *
42  * Their primary use-case is to implement Vulkan fences and semaphores.
43  *
44  * syncobj have a kref reference count, but also have an optional file.
45  * The file is only created once the syncobj is exported.
46  * The file takes a reference on the kref.
47  */
48 
49 #include <drm/drmP.h>
50 #include <linux/file.h>
51 #include <linux/fs.h>
52 #include <linux/anon_inodes.h>
53 #include <linux/sync_file.h>
54 #include <linux/sched/signal.h>
55 
56 #include "drm_internal.h"
57 #include <drm/drm_syncobj.h>
58 
59 /**
60  * drm_syncobj_find - lookup and reference a sync object.
61  * @file_private: drm file private pointer
62  * @handle: sync object handle to lookup.
63  *
64  * Returns a reference to the syncobj pointed to by handle or NULL.
65  */
drm_syncobj_find(struct drm_file * file_private,u32 handle)66 struct drm_syncobj *drm_syncobj_find(struct drm_file *file_private,
67 				     u32 handle)
68 {
69 	struct drm_syncobj *syncobj;
70 
71 	spin_lock(&file_private->syncobj_table_lock);
72 
73 	/* Check if we currently have a reference on the object */
74 	syncobj = idr_find(&file_private->syncobj_idr, handle);
75 	if (syncobj)
76 		drm_syncobj_get(syncobj);
77 
78 	spin_unlock(&file_private->syncobj_table_lock);
79 
80 	return syncobj;
81 }
82 EXPORT_SYMBOL(drm_syncobj_find);
83 
drm_syncobj_add_callback_locked(struct drm_syncobj * syncobj,struct drm_syncobj_cb * cb,drm_syncobj_func_t func)84 static void drm_syncobj_add_callback_locked(struct drm_syncobj *syncobj,
85 					    struct drm_syncobj_cb *cb,
86 					    drm_syncobj_func_t func)
87 {
88 	cb->func = func;
89 	list_add_tail(&cb->node, &syncobj->cb_list);
90 }
91 
drm_syncobj_fence_get_or_add_callback(struct drm_syncobj * syncobj,struct dma_fence ** fence,struct drm_syncobj_cb * cb,drm_syncobj_func_t func)92 static int drm_syncobj_fence_get_or_add_callback(struct drm_syncobj *syncobj,
93 						 struct dma_fence **fence,
94 						 struct drm_syncobj_cb *cb,
95 						 drm_syncobj_func_t func)
96 {
97 	int ret;
98 
99 	WARN_ON(*fence);
100 
101 	*fence = drm_syncobj_fence_get(syncobj);
102 	if (*fence)
103 		return 1;
104 
105 	spin_lock(&syncobj->lock);
106 	/* We've already tried once to get a fence and failed.  Now that we
107 	 * have the lock, try one more time just to be sure we don't add a
108 	 * callback when a fence has already been set.
109 	 */
110 	if (syncobj->fence) {
111 		*fence = dma_fence_get(syncobj->fence);
112 		ret = 1;
113 	} else {
114 		*fence = NULL;
115 		drm_syncobj_add_callback_locked(syncobj, cb, func);
116 		ret = 0;
117 	}
118 	spin_unlock(&syncobj->lock);
119 
120 	return ret;
121 }
122 
123 /**
124  * drm_syncobj_add_callback - adds a callback to syncobj::cb_list
125  * @syncobj: Sync object to which to add the callback
126  * @cb: Callback to add
127  * @func: Func to use when initializing the drm_syncobj_cb struct
128  *
129  * This adds a callback to be called next time the fence is replaced
130  */
drm_syncobj_add_callback(struct drm_syncobj * syncobj,struct drm_syncobj_cb * cb,drm_syncobj_func_t func)131 void drm_syncobj_add_callback(struct drm_syncobj *syncobj,
132 			      struct drm_syncobj_cb *cb,
133 			      drm_syncobj_func_t func)
134 {
135 	spin_lock(&syncobj->lock);
136 	drm_syncobj_add_callback_locked(syncobj, cb, func);
137 	spin_unlock(&syncobj->lock);
138 }
139 EXPORT_SYMBOL(drm_syncobj_add_callback);
140 
141 /**
142  * drm_syncobj_add_callback - removes a callback to syncobj::cb_list
143  * @syncobj: Sync object from which to remove the callback
144  * @cb: Callback to remove
145  */
drm_syncobj_remove_callback(struct drm_syncobj * syncobj,struct drm_syncobj_cb * cb)146 void drm_syncobj_remove_callback(struct drm_syncobj *syncobj,
147 				 struct drm_syncobj_cb *cb)
148 {
149 	spin_lock(&syncobj->lock);
150 	list_del_init(&cb->node);
151 	spin_unlock(&syncobj->lock);
152 }
153 EXPORT_SYMBOL(drm_syncobj_remove_callback);
154 
155 /**
156  * drm_syncobj_replace_fence - replace fence in a sync object.
157  * @syncobj: Sync object to replace fence in
158  * @fence: fence to install in sync file.
159  *
160  * This replaces the fence on a sync object.
161  */
drm_syncobj_replace_fence(struct drm_syncobj * syncobj,struct dma_fence * fence)162 void drm_syncobj_replace_fence(struct drm_syncobj *syncobj,
163 			       struct dma_fence *fence)
164 {
165 	struct dma_fence *old_fence;
166 	struct drm_syncobj_cb *cur, *tmp;
167 
168 	if (fence)
169 		dma_fence_get(fence);
170 
171 	spin_lock(&syncobj->lock);
172 
173 	old_fence = syncobj->fence;
174 	syncobj->fence = fence;
175 
176 	if (fence != old_fence) {
177 		list_for_each_entry_safe(cur, tmp, &syncobj->cb_list, node) {
178 			list_del_init(&cur->node);
179 			cur->func(syncobj, cur);
180 		}
181 	}
182 
183 	spin_unlock(&syncobj->lock);
184 
185 	dma_fence_put(old_fence);
186 }
187 EXPORT_SYMBOL(drm_syncobj_replace_fence);
188 
189 struct drm_syncobj_null_fence {
190 	struct dma_fence base;
191 	spinlock_t lock;
192 };
193 
drm_syncobj_null_fence_get_name(struct dma_fence * fence)194 static const char *drm_syncobj_null_fence_get_name(struct dma_fence *fence)
195 {
196         return "syncobjnull";
197 }
198 
drm_syncobj_null_fence_enable_signaling(struct dma_fence * fence)199 static bool drm_syncobj_null_fence_enable_signaling(struct dma_fence *fence)
200 {
201     dma_fence_enable_sw_signaling(fence);
202     return !dma_fence_is_signaled(fence);
203 }
204 
205 static const struct dma_fence_ops drm_syncobj_null_fence_ops = {
206 	.get_driver_name = drm_syncobj_null_fence_get_name,
207 	.get_timeline_name = drm_syncobj_null_fence_get_name,
208 	.enable_signaling = drm_syncobj_null_fence_enable_signaling,
209 	.wait = dma_fence_default_wait,
210 	.release = NULL,
211 };
212 
drm_syncobj_assign_null_handle(struct drm_syncobj * syncobj)213 static int drm_syncobj_assign_null_handle(struct drm_syncobj *syncobj)
214 {
215 	struct drm_syncobj_null_fence *fence;
216 	fence = kzalloc(sizeof(*fence), GFP_KERNEL);
217 	if (fence == NULL)
218 		return -ENOMEM;
219 
220 	spin_lock_init(&fence->lock);
221 	dma_fence_init(&fence->base, &drm_syncobj_null_fence_ops,
222 		       &fence->lock, 0, 0);
223 	dma_fence_signal(&fence->base);
224 
225 	drm_syncobj_replace_fence(syncobj, &fence->base);
226 
227 	dma_fence_put(&fence->base);
228 
229 	return 0;
230 }
231 
drm_syncobj_find_fence(struct drm_file * file_private,u32 handle,struct dma_fence ** fence)232 int drm_syncobj_find_fence(struct drm_file *file_private,
233 			   u32 handle,
234 			   struct dma_fence **fence)
235 {
236 	struct drm_syncobj *syncobj = drm_syncobj_find(file_private, handle);
237 	int ret = 0;
238 
239 	if (!syncobj)
240 		return -ENOENT;
241 
242 	*fence = drm_syncobj_fence_get(syncobj);
243 	if (!*fence) {
244 		ret = -EINVAL;
245 	}
246 	drm_syncobj_put(syncobj);
247 	return ret;
248 }
249 EXPORT_SYMBOL(drm_syncobj_find_fence);
250 
251 /**
252  * drm_syncobj_free - free a sync object.
253  * @kref: kref to free.
254  *
255  * Only to be called from kref_put in drm_syncobj_put.
256  */
drm_syncobj_free(struct kref * kref)257 void drm_syncobj_free(struct kref *kref)
258 {
259 	struct drm_syncobj *syncobj = container_of(kref,
260 						   struct drm_syncobj,
261 						   refcount);
262 	drm_syncobj_replace_fence(syncobj, NULL);
263 	kfree(syncobj);
264 }
265 EXPORT_SYMBOL(drm_syncobj_free);
266 
drm_syncobj_create(struct drm_file * file_private,u32 * handle,uint32_t flags)267 static int drm_syncobj_create(struct drm_file *file_private,
268 			      u32 *handle, uint32_t flags)
269 {
270 	int ret;
271 	struct drm_syncobj *syncobj;
272 
273 	syncobj = kzalloc(sizeof(struct drm_syncobj), GFP_KERNEL);
274 	if (!syncobj)
275 		return -ENOMEM;
276 
277 	kref_init(&syncobj->refcount);
278 	INIT_LIST_HEAD(&syncobj->cb_list);
279 	spin_lock_init(&syncobj->lock);
280 
281 	if (flags & DRM_SYNCOBJ_CREATE_SIGNALED) {
282 		ret = drm_syncobj_assign_null_handle(syncobj);
283 		if (ret < 0) {
284 			drm_syncobj_put(syncobj);
285 			return ret;
286 		}
287 	}
288 
289 	idr_preload(GFP_KERNEL);
290 	spin_lock(&file_private->syncobj_table_lock);
291 	ret = idr_alloc(&file_private->syncobj_idr, syncobj, 1, 0, GFP_NOWAIT);
292 	spin_unlock(&file_private->syncobj_table_lock);
293 
294 	idr_preload_end();
295 
296 	if (ret < 0) {
297 		drm_syncobj_put(syncobj);
298 		return ret;
299 	}
300 
301 	*handle = ret;
302 	return 0;
303 }
304 
drm_syncobj_destroy(struct drm_file * file_private,u32 handle)305 static int drm_syncobj_destroy(struct drm_file *file_private,
306 			       u32 handle)
307 {
308 	struct drm_syncobj *syncobj;
309 
310 	spin_lock(&file_private->syncobj_table_lock);
311 	syncobj = idr_remove(&file_private->syncobj_idr, handle);
312 	spin_unlock(&file_private->syncobj_table_lock);
313 
314 	if (!syncobj)
315 		return -EINVAL;
316 
317 	drm_syncobj_put(syncobj);
318 	return 0;
319 }
320 
drm_syncobj_file_release(struct inode * inode,struct file * file)321 static int drm_syncobj_file_release(struct inode *inode, struct file *file)
322 {
323 	struct drm_syncobj *syncobj = file->private_data;
324 
325 	drm_syncobj_put(syncobj);
326 	return 0;
327 }
328 
329 static const struct file_operations drm_syncobj_file_fops = {
330 	.release = drm_syncobj_file_release,
331 };
332 
drm_syncobj_handle_to_fd(struct drm_file * file_private,u32 handle,int * p_fd)333 static int drm_syncobj_handle_to_fd(struct drm_file *file_private,
334 				    u32 handle, int *p_fd)
335 {
336 	struct drm_syncobj *syncobj = drm_syncobj_find(file_private, handle);
337 	struct file *file;
338 	int fd;
339 
340 	if (!syncobj)
341 		return -EINVAL;
342 
343 	fd = get_unused_fd_flags(O_CLOEXEC);
344 	if (fd < 0) {
345 		drm_syncobj_put(syncobj);
346 		return fd;
347 	}
348 
349 	file = anon_inode_getfile("syncobj_file",
350 				  &drm_syncobj_file_fops,
351 				  syncobj, 0);
352 	if (IS_ERR(file)) {
353 		put_unused_fd(fd);
354 		drm_syncobj_put(syncobj);
355 		return PTR_ERR(file);
356 	}
357 
358 	drm_syncobj_get(syncobj);
359 	fd_install(fd, file);
360 
361 	*p_fd = fd;
362 	return 0;
363 }
364 
drm_syncobj_fd_to_handle(struct drm_file * file_private,int fd,u32 * handle)365 static int drm_syncobj_fd_to_handle(struct drm_file *file_private,
366 				    int fd, u32 *handle)
367 {
368 	struct drm_syncobj *syncobj;
369 	struct file *file;
370 	int ret;
371 
372 	file = fget(fd);
373 	if (!file)
374 		return -EINVAL;
375 
376 	if (file->f_op != &drm_syncobj_file_fops) {
377 		fput(file);
378 		return -EINVAL;
379 	}
380 
381 	/* take a reference to put in the idr */
382 	syncobj = file->private_data;
383 	drm_syncobj_get(syncobj);
384 
385 	idr_preload(GFP_KERNEL);
386 	spin_lock(&file_private->syncobj_table_lock);
387 	ret = idr_alloc(&file_private->syncobj_idr, syncobj, 1, 0, GFP_NOWAIT);
388 	spin_unlock(&file_private->syncobj_table_lock);
389 	idr_preload_end();
390 
391 	if (ret > 0) {
392 		*handle = ret;
393 		ret = 0;
394 	} else
395 		drm_syncobj_put(syncobj);
396 
397 	fput(file);
398 	return ret;
399 }
400 
drm_syncobj_import_sync_file_fence(struct drm_file * file_private,int fd,int handle)401 int drm_syncobj_import_sync_file_fence(struct drm_file *file_private,
402 				       int fd, int handle)
403 {
404 	struct dma_fence *fence = sync_file_get_fence(fd);
405 	struct drm_syncobj *syncobj;
406 
407 	if (!fence)
408 		return -EINVAL;
409 
410 	syncobj = drm_syncobj_find(file_private, handle);
411 	if (!syncobj) {
412 		dma_fence_put(fence);
413 		return -ENOENT;
414 	}
415 
416 	drm_syncobj_replace_fence(syncobj, fence);
417 	dma_fence_put(fence);
418 	drm_syncobj_put(syncobj);
419 	return 0;
420 }
421 
drm_syncobj_export_sync_file(struct drm_file * file_private,int handle,int * p_fd)422 int drm_syncobj_export_sync_file(struct drm_file *file_private,
423 				 int handle, int *p_fd)
424 {
425 	int ret;
426 	struct dma_fence *fence;
427 	struct sync_file *sync_file;
428 	int fd = get_unused_fd_flags(O_CLOEXEC);
429 
430 	if (fd < 0)
431 		return fd;
432 
433 	ret = drm_syncobj_find_fence(file_private, handle, &fence);
434 	if (ret)
435 		goto err_put_fd;
436 
437 	sync_file = sync_file_create(fence);
438 
439 	dma_fence_put(fence);
440 
441 	if (!sync_file) {
442 		ret = -EINVAL;
443 		goto err_put_fd;
444 	}
445 
446 	fd_install(fd, sync_file->file);
447 
448 	*p_fd = fd;
449 	return 0;
450 err_put_fd:
451 	put_unused_fd(fd);
452 	return ret;
453 }
454 /**
455  * drm_syncobj_open - initalizes syncobj file-private structures at devnode open time
456  * @file_private: drm file-private structure to set up
457  *
458  * Called at device open time, sets up the structure for handling refcounting
459  * of sync objects.
460  */
461 void
drm_syncobj_open(struct drm_file * file_private)462 drm_syncobj_open(struct drm_file *file_private)
463 {
464 	idr_init(&file_private->syncobj_idr);
465 	spin_lock_init(&file_private->syncobj_table_lock);
466 }
467 
468 static int
drm_syncobj_release_handle(int id,void * ptr,void * data)469 drm_syncobj_release_handle(int id, void *ptr, void *data)
470 {
471 	struct drm_syncobj *syncobj = ptr;
472 
473 	drm_syncobj_put(syncobj);
474 	return 0;
475 }
476 
477 /**
478  * drm_syncobj_release - release file-private sync object resources
479  * @file_private: drm file-private structure to clean up
480  *
481  * Called at close time when the filp is going away.
482  *
483  * Releases any remaining references on objects by this filp.
484  */
485 void
drm_syncobj_release(struct drm_file * file_private)486 drm_syncobj_release(struct drm_file *file_private)
487 {
488 	idr_for_each(&file_private->syncobj_idr,
489 		     &drm_syncobj_release_handle, file_private);
490 	idr_destroy(&file_private->syncobj_idr);
491 }
492 
493 int
drm_syncobj_create_ioctl(struct drm_device * dev,void * data,struct drm_file * file_private)494 drm_syncobj_create_ioctl(struct drm_device *dev, void *data,
495 			 struct drm_file *file_private)
496 {
497 	struct drm_syncobj_create *args = data;
498 
499 	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
500 		return -ENODEV;
501 
502 	/* no valid flags yet */
503 	if (args->flags & ~DRM_SYNCOBJ_CREATE_SIGNALED)
504 		return -EINVAL;
505 
506 	return drm_syncobj_create(file_private,
507 				  &args->handle, args->flags);
508 }
509 
510 int
drm_syncobj_destroy_ioctl(struct drm_device * dev,void * data,struct drm_file * file_private)511 drm_syncobj_destroy_ioctl(struct drm_device *dev, void *data,
512 			  struct drm_file *file_private)
513 {
514 	struct drm_syncobj_destroy *args = data;
515 
516 	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
517 		return -ENODEV;
518 
519 	/* make sure padding is empty */
520 	if (args->pad)
521 		return -EINVAL;
522 	return drm_syncobj_destroy(file_private, args->handle);
523 }
524 
525 int
drm_syncobj_handle_to_fd_ioctl(struct drm_device * dev,void * data,struct drm_file * file_private)526 drm_syncobj_handle_to_fd_ioctl(struct drm_device *dev, void *data,
527 				   struct drm_file *file_private)
528 {
529 	struct drm_syncobj_handle *args = data;
530 
531 	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
532 		return -ENODEV;
533 
534 	if (args->pad)
535 		return -EINVAL;
536 
537 	if (args->flags != 0 &&
538 	    args->flags != DRM_SYNCOBJ_HANDLE_TO_FD_FLAGS_EXPORT_SYNC_FILE)
539 		return -EINVAL;
540 
541 	if (args->flags & DRM_SYNCOBJ_HANDLE_TO_FD_FLAGS_EXPORT_SYNC_FILE)
542 		return drm_syncobj_export_sync_file(file_private, args->handle,
543 						    &args->fd);
544 
545 	return drm_syncobj_handle_to_fd(file_private, args->handle,
546 					&args->fd);
547 }
548 
549 int
drm_syncobj_fd_to_handle_ioctl(struct drm_device * dev,void * data,struct drm_file * file_private)550 drm_syncobj_fd_to_handle_ioctl(struct drm_device *dev, void *data,
551 				   struct drm_file *file_private)
552 {
553 	struct drm_syncobj_handle *args = data;
554 
555 	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
556 		return -ENODEV;
557 
558 	if (args->pad)
559 		return -EINVAL;
560 
561 	if (args->flags != 0 &&
562 	    args->flags != DRM_SYNCOBJ_FD_TO_HANDLE_FLAGS_IMPORT_SYNC_FILE)
563 		return -EINVAL;
564 
565 	if (args->flags & DRM_SYNCOBJ_FD_TO_HANDLE_FLAGS_IMPORT_SYNC_FILE)
566 		return drm_syncobj_import_sync_file_fence(file_private,
567 							  args->fd,
568 							  args->handle);
569 
570 	return drm_syncobj_fd_to_handle(file_private, args->fd,
571 					&args->handle);
572 }
573 
574 struct syncobj_wait_entry {
575 	struct task_struct *task;
576 	struct dma_fence *fence;
577 	struct dma_fence_cb fence_cb;
578 	struct drm_syncobj_cb syncobj_cb;
579 };
580 
syncobj_wait_fence_func(struct dma_fence * fence,struct dma_fence_cb * cb)581 static void syncobj_wait_fence_func(struct dma_fence *fence,
582 				    struct dma_fence_cb *cb)
583 {
584 	struct syncobj_wait_entry *wait =
585 		container_of(cb, struct syncobj_wait_entry, fence_cb);
586 
587 	wake_up_process(wait->task);
588 }
589 
syncobj_wait_syncobj_func(struct drm_syncobj * syncobj,struct drm_syncobj_cb * cb)590 static void syncobj_wait_syncobj_func(struct drm_syncobj *syncobj,
591 				      struct drm_syncobj_cb *cb)
592 {
593 	struct syncobj_wait_entry *wait =
594 		container_of(cb, struct syncobj_wait_entry, syncobj_cb);
595 
596 	/* This happens inside the syncobj lock */
597 	wait->fence = dma_fence_get(syncobj->fence);
598 	wake_up_process(wait->task);
599 }
600 
drm_syncobj_array_wait_timeout(struct drm_syncobj ** syncobjs,uint32_t count,uint32_t flags,signed long timeout,uint32_t * idx)601 static signed long drm_syncobj_array_wait_timeout(struct drm_syncobj **syncobjs,
602 						  uint32_t count,
603 						  uint32_t flags,
604 						  signed long timeout,
605 						  uint32_t *idx)
606 {
607 	struct syncobj_wait_entry *entries;
608 	struct dma_fence *fence;
609 	signed long ret;
610 	uint32_t signaled_count, i;
611 
612 	entries = kcalloc(count, sizeof(*entries), GFP_KERNEL);
613 	if (!entries)
614 		return -ENOMEM;
615 
616 	/* Walk the list of sync objects and initialize entries.  We do
617 	 * this up-front so that we can properly return -EINVAL if there is
618 	 * a syncobj with a missing fence and then never have the chance of
619 	 * returning -EINVAL again.
620 	 */
621 	signaled_count = 0;
622 	for (i = 0; i < count; ++i) {
623 		entries[i].task = current;
624 		entries[i].fence = drm_syncobj_fence_get(syncobjs[i]);
625 		if (!entries[i].fence) {
626 			if (flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT) {
627 				continue;
628 			} else {
629 				ret = -EINVAL;
630 				goto cleanup_entries;
631 			}
632 		}
633 
634 		if (dma_fence_is_signaled(entries[i].fence)) {
635 			if (signaled_count == 0 && idx)
636 				*idx = i;
637 			signaled_count++;
638 		}
639 	}
640 
641 	/* Initialize ret to the max of timeout and 1.  That way, the
642 	 * default return value indicates a successful wait and not a
643 	 * timeout.
644 	 */
645 	ret = max_t(signed long, timeout, 1);
646 
647 	if (signaled_count == count ||
648 	    (signaled_count > 0 &&
649 	     !(flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL)))
650 		goto cleanup_entries;
651 
652 	/* There's a very annoying laxness in the dma_fence API here, in
653 	 * that backends are not required to automatically report when a
654 	 * fence is signaled prior to fence->ops->enable_signaling() being
655 	 * called.  So here if we fail to match signaled_count, we need to
656 	 * fallthough and try a 0 timeout wait!
657 	 */
658 
659 	if (flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT) {
660 		for (i = 0; i < count; ++i) {
661 			if (entries[i].fence)
662 				continue;
663 
664 			drm_syncobj_fence_get_or_add_callback(syncobjs[i],
665 							      &entries[i].fence,
666 							      &entries[i].syncobj_cb,
667 							      syncobj_wait_syncobj_func);
668 		}
669 	}
670 
671 	do {
672 		set_current_state(TASK_INTERRUPTIBLE);
673 
674 		signaled_count = 0;
675 		for (i = 0; i < count; ++i) {
676 			fence = entries[i].fence;
677 			if (!fence)
678 				continue;
679 
680 			if (dma_fence_is_signaled(fence) ||
681 			    (!entries[i].fence_cb.func &&
682 			     dma_fence_add_callback(fence,
683 						    &entries[i].fence_cb,
684 						    syncobj_wait_fence_func))) {
685 				/* The fence has been signaled */
686 				if (flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL) {
687 					signaled_count++;
688 				} else {
689 					if (idx)
690 						*idx = i;
691 					goto done_waiting;
692 				}
693 			}
694 		}
695 
696 		if (signaled_count == count)
697 			goto done_waiting;
698 
699 		if (timeout == 0) {
700 			/* If we are doing a 0 timeout wait and we got
701 			 * here, then we just timed out.
702 			 */
703 			ret = 0;
704 			goto done_waiting;
705 		}
706 
707 		ret = schedule_timeout(ret);
708 
709 		if (ret > 0 && signal_pending(current))
710 			ret = -ERESTARTSYS;
711 	} while (ret > 0);
712 
713 done_waiting:
714 	__set_current_state(TASK_RUNNING);
715 
716 cleanup_entries:
717 	for (i = 0; i < count; ++i) {
718 		if (entries[i].syncobj_cb.func)
719 			drm_syncobj_remove_callback(syncobjs[i],
720 						    &entries[i].syncobj_cb);
721 		if (entries[i].fence_cb.func)
722 			dma_fence_remove_callback(entries[i].fence,
723 						  &entries[i].fence_cb);
724 		dma_fence_put(entries[i].fence);
725 	}
726 	kfree(entries);
727 
728 	return ret;
729 }
730 
731 /**
732  * drm_timeout_abs_to_jiffies - calculate jiffies timeout from absolute value
733  *
734  * @timeout_nsec: timeout nsec component in ns, 0 for poll
735  *
736  * Calculate the timeout in jiffies from an absolute time in sec/nsec.
737  */
drm_timeout_abs_to_jiffies(int64_t timeout_nsec)738 static signed long drm_timeout_abs_to_jiffies(int64_t timeout_nsec)
739 {
740 	ktime_t abs_timeout, now;
741 	u64 timeout_ns, timeout_jiffies64;
742 
743 	/* make 0 timeout means poll - absolute 0 doesn't seem valid */
744 	if (timeout_nsec == 0)
745 		return 0;
746 
747 	abs_timeout = ns_to_ktime(timeout_nsec);
748 	now = ktime_get();
749 
750 	if (!ktime_after(abs_timeout, now))
751 		return 0;
752 
753 	timeout_ns = ktime_to_ns(ktime_sub(abs_timeout, now));
754 
755 	timeout_jiffies64 = nsecs_to_jiffies64(timeout_ns);
756 	/*  clamp timeout to avoid infinite timeout */
757 	if (timeout_jiffies64 >= MAX_SCHEDULE_TIMEOUT - 1)
758 		return MAX_SCHEDULE_TIMEOUT - 1;
759 
760 	return timeout_jiffies64 + 1;
761 }
762 
drm_syncobj_array_wait(struct drm_device * dev,struct drm_file * file_private,struct drm_syncobj_wait * wait,struct drm_syncobj ** syncobjs)763 static int drm_syncobj_array_wait(struct drm_device *dev,
764 				  struct drm_file *file_private,
765 				  struct drm_syncobj_wait *wait,
766 				  struct drm_syncobj **syncobjs)
767 {
768 	signed long timeout = drm_timeout_abs_to_jiffies(wait->timeout_nsec);
769 	signed long ret = 0;
770 	uint32_t first = ~0;
771 
772 	ret = drm_syncobj_array_wait_timeout(syncobjs,
773 					     wait->count_handles,
774 					     wait->flags,
775 					     timeout, &first);
776 	if (ret < 0)
777 		return ret;
778 
779 	wait->first_signaled = first;
780 	if (ret == 0)
781 		return -ETIME;
782 	return 0;
783 }
784 
drm_syncobj_array_find(struct drm_file * file_private,void * user_handles,uint32_t count_handles,struct drm_syncobj *** syncobjs_out)785 static int drm_syncobj_array_find(struct drm_file *file_private,
786 				  void *user_handles, uint32_t count_handles,
787 				  struct drm_syncobj ***syncobjs_out)
788 {
789 	uint32_t i, *handles;
790 	struct drm_syncobj **syncobjs;
791 	int ret;
792 
793 	handles = kmalloc_array(count_handles, sizeof(*handles), GFP_KERNEL);
794 	if (handles == NULL)
795 		return -ENOMEM;
796 
797 	if (copy_from_user(handles, user_handles,
798 			   sizeof(uint32_t) * count_handles)) {
799 		ret = -EFAULT;
800 		goto err_free_handles;
801 	}
802 
803 	syncobjs = kmalloc_array(count_handles, sizeof(*syncobjs), GFP_KERNEL);
804 	if (syncobjs == NULL) {
805 		ret = -ENOMEM;
806 		goto err_free_handles;
807 	}
808 
809 	for (i = 0; i < count_handles; i++) {
810 		syncobjs[i] = drm_syncobj_find(file_private, handles[i]);
811 		if (!syncobjs[i]) {
812 			ret = -ENOENT;
813 			goto err_put_syncobjs;
814 		}
815 	}
816 
817 	kfree(handles);
818 	*syncobjs_out = syncobjs;
819 	return 0;
820 
821 err_put_syncobjs:
822 	while (i-- > 0)
823 		drm_syncobj_put(syncobjs[i]);
824 	kfree(syncobjs);
825 err_free_handles:
826 	kfree(handles);
827 
828 	return ret;
829 }
830 
drm_syncobj_array_free(struct drm_syncobj ** syncobjs,uint32_t count)831 static void drm_syncobj_array_free(struct drm_syncobj **syncobjs,
832 				   uint32_t count)
833 {
834 	uint32_t i;
835 	for (i = 0; i < count; i++)
836 		drm_syncobj_put(syncobjs[i]);
837 	kfree(syncobjs);
838 }
839 
840 int
drm_syncobj_wait_ioctl(struct drm_device * dev,void * data,struct drm_file * file_private)841 drm_syncobj_wait_ioctl(struct drm_device *dev, void *data,
842 		       struct drm_file *file_private)
843 {
844 	struct drm_syncobj_wait *args = data;
845 	struct drm_syncobj **syncobjs;
846 	int ret = 0;
847 
848 	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
849 		return -ENODEV;
850 
851 	if (args->flags & ~(DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL |
852 			    DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT))
853 		return -EINVAL;
854 
855 	if (args->count_handles == 0)
856 		return -EINVAL;
857 
858 	ret = drm_syncobj_array_find(file_private,
859 				     u64_to_user_ptr(args->handles),
860 				     args->count_handles,
861 				     &syncobjs);
862 	if (ret < 0)
863 		return ret;
864 
865 	ret = drm_syncobj_array_wait(dev, file_private,
866 				     args, syncobjs);
867 
868 	drm_syncobj_array_free(syncobjs, args->count_handles);
869 
870 	return ret;
871 }
872 
873 int
drm_syncobj_reset_ioctl(struct drm_device * dev,void * data,struct drm_file * file_private)874 drm_syncobj_reset_ioctl(struct drm_device *dev, void *data,
875 			struct drm_file *file_private)
876 {
877 	struct drm_syncobj_array *args = data;
878 	struct drm_syncobj **syncobjs;
879 	uint32_t i;
880 	int ret;
881 
882 	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
883 		return -ENODEV;
884 
885 	if (args->pad != 0)
886 		return -EINVAL;
887 
888 	if (args->count_handles == 0)
889 		return -EINVAL;
890 
891 	ret = drm_syncobj_array_find(file_private,
892 				     u64_to_user_ptr(args->handles),
893 				     args->count_handles,
894 				     &syncobjs);
895 	if (ret < 0)
896 		return ret;
897 
898 	for (i = 0; i < args->count_handles; i++)
899 		drm_syncobj_replace_fence(syncobjs[i], NULL);
900 
901 	drm_syncobj_array_free(syncobjs, args->count_handles);
902 
903 	return 0;
904 }
905 
906 int
drm_syncobj_signal_ioctl(struct drm_device * dev,void * data,struct drm_file * file_private)907 drm_syncobj_signal_ioctl(struct drm_device *dev, void *data,
908 			 struct drm_file *file_private)
909 {
910 	struct drm_syncobj_array *args = data;
911 	struct drm_syncobj **syncobjs;
912 	uint32_t i;
913 	int ret;
914 
915 	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
916 		return -ENODEV;
917 
918 	if (args->pad != 0)
919 		return -EINVAL;
920 
921 	if (args->count_handles == 0)
922 		return -EINVAL;
923 
924 	ret = drm_syncobj_array_find(file_private,
925 				     u64_to_user_ptr(args->handles),
926 				     args->count_handles,
927 				     &syncobjs);
928 	if (ret < 0)
929 		return ret;
930 
931 	for (i = 0; i < args->count_handles; i++) {
932 		ret = drm_syncobj_assign_null_handle(syncobjs[i]);
933 		if (ret < 0)
934 			break;
935 	}
936 
937 	drm_syncobj_array_free(syncobjs, args->count_handles);
938 
939 	return ret;
940 }
941