xref: /openbmc/linux/drivers/gpu/drm/drm_file.c (revision 5ff32883)
1 /*
2  * \author Rickard E. (Rik) Faith <faith@valinux.com>
3  * \author Daryll Strauss <daryll@valinux.com>
4  * \author Gareth Hughes <gareth@valinux.com>
5  */
6 
7 /*
8  * Created: Mon Jan  4 08:58:31 1999 by faith@valinux.com
9  *
10  * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
11  * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
12  * All Rights Reserved.
13  *
14  * Permission is hereby granted, free of charge, to any person obtaining a
15  * copy of this software and associated documentation files (the "Software"),
16  * to deal in the Software without restriction, including without limitation
17  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
18  * and/or sell copies of the Software, and to permit persons to whom the
19  * Software is furnished to do so, subject to the following conditions:
20  *
21  * The above copyright notice and this permission notice (including the next
22  * paragraph) shall be included in all copies or substantial portions of the
23  * Software.
24  *
25  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
26  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
27  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
28  * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
29  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
30  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
31  * OTHER DEALINGS IN THE SOFTWARE.
32  */
33 
34 #include <linux/poll.h>
35 #include <linux/slab.h>
36 #include <linux/module.h>
37 
38 #include <drm/drm_client.h>
39 #include <drm/drm_file.h>
40 #include <drm/drmP.h>
41 
42 #include "drm_legacy.h"
43 #include "drm_internal.h"
44 #include "drm_crtc_internal.h"
45 
46 /* from BKL pushdown */
47 DEFINE_MUTEX(drm_global_mutex);
48 
49 /**
50  * DOC: file operations
51  *
52  * Drivers must define the file operations structure that forms the DRM
53  * userspace API entry point, even though most of those operations are
54  * implemented in the DRM core. The resulting &struct file_operations must be
55  * stored in the &drm_driver.fops field. The mandatory functions are drm_open(),
56  * drm_read(), drm_ioctl() and drm_compat_ioctl() if CONFIG_COMPAT is enabled
57  * Note that drm_compat_ioctl will be NULL if CONFIG_COMPAT=n, so there's no
58  * need to sprinkle #ifdef into the code. Drivers which implement private ioctls
59  * that require 32/64 bit compatibility support must provide their own
60  * &file_operations.compat_ioctl handler that processes private ioctls and calls
61  * drm_compat_ioctl() for core ioctls.
62  *
63  * In addition drm_read() and drm_poll() provide support for DRM events. DRM
64  * events are a generic and extensible means to send asynchronous events to
65  * userspace through the file descriptor. They are used to send vblank event and
66  * page flip completions by the KMS API. But drivers can also use it for their
67  * own needs, e.g. to signal completion of rendering.
68  *
69  * For the driver-side event interface see drm_event_reserve_init() and
70  * drm_send_event() as the main starting points.
71  *
72  * The memory mapping implementation will vary depending on how the driver
73  * manages memory. Legacy drivers will use the deprecated drm_legacy_mmap()
74  * function, modern drivers should use one of the provided memory-manager
75  * specific implementations. For GEM-based drivers this is drm_gem_mmap(), and
76  * for drivers which use the CMA GEM helpers it's drm_gem_cma_mmap().
77  *
78  * No other file operations are supported by the DRM userspace API. Overall the
79  * following is an example &file_operations structure::
80  *
81  *     static const example_drm_fops = {
82  *             .owner = THIS_MODULE,
83  *             .open = drm_open,
84  *             .release = drm_release,
85  *             .unlocked_ioctl = drm_ioctl,
86  *             .compat_ioctl = drm_compat_ioctl, // NULL if CONFIG_COMPAT=n
87  *             .poll = drm_poll,
88  *             .read = drm_read,
89  *             .llseek = no_llseek,
90  *             .mmap = drm_gem_mmap,
91  *     };
92  *
93  * For plain GEM based drivers there is the DEFINE_DRM_GEM_FOPS() macro, and for
94  * CMA based drivers there is the DEFINE_DRM_GEM_CMA_FOPS() macro to make this
95  * simpler.
96  *
97  * The driver's &file_operations must be stored in &drm_driver.fops.
98  *
99  * For driver-private IOCTL handling see the more detailed discussion in
100  * :ref:`IOCTL support in the userland interfaces chapter<drm_driver_ioctl>`.
101  */
102 
103 static int drm_open_helper(struct file *filp, struct drm_minor *minor);
104 
105 /**
106  * drm_file_alloc - allocate file context
107  * @minor: minor to allocate on
108  *
109  * This allocates a new DRM file context. It is not linked into any context and
110  * can be used by the caller freely. Note that the context keeps a pointer to
111  * @minor, so it must be freed before @minor is.
112  *
113  * RETURNS:
114  * Pointer to newly allocated context, ERR_PTR on failure.
115  */
116 struct drm_file *drm_file_alloc(struct drm_minor *minor)
117 {
118 	struct drm_device *dev = minor->dev;
119 	struct drm_file *file;
120 	int ret;
121 
122 	file = kzalloc(sizeof(*file), GFP_KERNEL);
123 	if (!file)
124 		return ERR_PTR(-ENOMEM);
125 
126 	file->pid = get_pid(task_pid(current));
127 	file->minor = minor;
128 
129 	/* for compatibility root is always authenticated */
130 	file->authenticated = capable(CAP_SYS_ADMIN);
131 	file->lock_count = 0;
132 
133 	INIT_LIST_HEAD(&file->lhead);
134 	INIT_LIST_HEAD(&file->fbs);
135 	mutex_init(&file->fbs_lock);
136 	INIT_LIST_HEAD(&file->blobs);
137 	INIT_LIST_HEAD(&file->pending_event_list);
138 	INIT_LIST_HEAD(&file->event_list);
139 	init_waitqueue_head(&file->event_wait);
140 	file->event_space = 4096; /* set aside 4k for event buffer */
141 
142 	mutex_init(&file->event_read_lock);
143 
144 	if (drm_core_check_feature(dev, DRIVER_GEM))
145 		drm_gem_open(dev, file);
146 
147 	if (drm_core_check_feature(dev, DRIVER_SYNCOBJ))
148 		drm_syncobj_open(file);
149 
150 	if (drm_core_check_feature(dev, DRIVER_PRIME))
151 		drm_prime_init_file_private(&file->prime);
152 
153 	if (dev->driver->open) {
154 		ret = dev->driver->open(dev, file);
155 		if (ret < 0)
156 			goto out_prime_destroy;
157 	}
158 
159 	return file;
160 
161 out_prime_destroy:
162 	if (drm_core_check_feature(dev, DRIVER_PRIME))
163 		drm_prime_destroy_file_private(&file->prime);
164 	if (drm_core_check_feature(dev, DRIVER_SYNCOBJ))
165 		drm_syncobj_release(file);
166 	if (drm_core_check_feature(dev, DRIVER_GEM))
167 		drm_gem_release(dev, file);
168 	put_pid(file->pid);
169 	kfree(file);
170 
171 	return ERR_PTR(ret);
172 }
173 
174 static void drm_events_release(struct drm_file *file_priv)
175 {
176 	struct drm_device *dev = file_priv->minor->dev;
177 	struct drm_pending_event *e, *et;
178 	unsigned long flags;
179 
180 	spin_lock_irqsave(&dev->event_lock, flags);
181 
182 	/* Unlink pending events */
183 	list_for_each_entry_safe(e, et, &file_priv->pending_event_list,
184 				 pending_link) {
185 		list_del(&e->pending_link);
186 		e->file_priv = NULL;
187 	}
188 
189 	/* Remove unconsumed events */
190 	list_for_each_entry_safe(e, et, &file_priv->event_list, link) {
191 		list_del(&e->link);
192 		kfree(e);
193 	}
194 
195 	spin_unlock_irqrestore(&dev->event_lock, flags);
196 }
197 
198 /**
199  * drm_file_free - free file context
200  * @file: context to free, or NULL
201  *
202  * This destroys and deallocates a DRM file context previously allocated via
203  * drm_file_alloc(). The caller must make sure to unlink it from any contexts
204  * before calling this.
205  *
206  * If NULL is passed, this is a no-op.
207  *
208  * RETURNS:
209  * 0 on success, or error code on failure.
210  */
211 void drm_file_free(struct drm_file *file)
212 {
213 	struct drm_device *dev;
214 
215 	if (!file)
216 		return;
217 
218 	dev = file->minor->dev;
219 
220 	DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
221 		  task_pid_nr(current),
222 		  (long)old_encode_dev(file->minor->kdev->devt),
223 		  dev->open_count);
224 
225 	if (drm_core_check_feature(dev, DRIVER_LEGACY) &&
226 	    dev->driver->preclose)
227 		dev->driver->preclose(dev, file);
228 
229 	if (drm_core_check_feature(dev, DRIVER_LEGACY))
230 		drm_legacy_lock_release(dev, file->filp);
231 
232 	if (drm_core_check_feature(dev, DRIVER_HAVE_DMA))
233 		drm_legacy_reclaim_buffers(dev, file);
234 
235 	drm_events_release(file);
236 
237 	if (drm_core_check_feature(dev, DRIVER_MODESET)) {
238 		drm_fb_release(file);
239 		drm_property_destroy_user_blobs(dev, file);
240 	}
241 
242 	if (drm_core_check_feature(dev, DRIVER_SYNCOBJ))
243 		drm_syncobj_release(file);
244 
245 	if (drm_core_check_feature(dev, DRIVER_GEM))
246 		drm_gem_release(dev, file);
247 
248 	drm_legacy_ctxbitmap_flush(dev, file);
249 
250 	if (drm_is_primary_client(file))
251 		drm_master_release(file);
252 
253 	if (dev->driver->postclose)
254 		dev->driver->postclose(dev, file);
255 
256 	if (drm_core_check_feature(dev, DRIVER_PRIME))
257 		drm_prime_destroy_file_private(&file->prime);
258 
259 	WARN_ON(!list_empty(&file->event_list));
260 
261 	put_pid(file->pid);
262 	kfree(file);
263 }
264 
265 static int drm_setup(struct drm_device * dev)
266 {
267 	int ret;
268 
269 	if (dev->driver->firstopen &&
270 	    drm_core_check_feature(dev, DRIVER_LEGACY)) {
271 		ret = dev->driver->firstopen(dev);
272 		if (ret != 0)
273 			return ret;
274 	}
275 
276 	ret = drm_legacy_dma_setup(dev);
277 	if (ret < 0)
278 		return ret;
279 
280 
281 	DRM_DEBUG("\n");
282 	return 0;
283 }
284 
285 /**
286  * drm_open - open method for DRM file
287  * @inode: device inode
288  * @filp: file pointer.
289  *
290  * This function must be used by drivers as their &file_operations.open method.
291  * It looks up the correct DRM device and instantiates all the per-file
292  * resources for it. It also calls the &drm_driver.open driver callback.
293  *
294  * RETURNS:
295  *
296  * 0 on success or negative errno value on falure.
297  */
298 int drm_open(struct inode *inode, struct file *filp)
299 {
300 	struct drm_device *dev;
301 	struct drm_minor *minor;
302 	int retcode;
303 	int need_setup = 0;
304 
305 	minor = drm_minor_acquire(iminor(inode));
306 	if (IS_ERR(minor))
307 		return PTR_ERR(minor);
308 
309 	dev = minor->dev;
310 	if (!dev->open_count++)
311 		need_setup = 1;
312 
313 	/* share address_space across all char-devs of a single device */
314 	filp->f_mapping = dev->anon_inode->i_mapping;
315 
316 	retcode = drm_open_helper(filp, minor);
317 	if (retcode)
318 		goto err_undo;
319 	if (need_setup) {
320 		retcode = drm_setup(dev);
321 		if (retcode)
322 			goto err_undo;
323 	}
324 	return 0;
325 
326 err_undo:
327 	dev->open_count--;
328 	drm_minor_release(minor);
329 	return retcode;
330 }
331 EXPORT_SYMBOL(drm_open);
332 
333 /*
334  * Check whether DRI will run on this CPU.
335  *
336  * \return non-zero if the DRI will run on this CPU, or zero otherwise.
337  */
338 static int drm_cpu_valid(void)
339 {
340 #if defined(__sparc__) && !defined(__sparc_v9__)
341 	return 0;		/* No cmpxchg before v9 sparc. */
342 #endif
343 	return 1;
344 }
345 
346 /*
347  * Called whenever a process opens /dev/drm.
348  *
349  * \param filp file pointer.
350  * \param minor acquired minor-object.
351  * \return zero on success or a negative number on failure.
352  *
353  * Creates and initializes a drm_file structure for the file private data in \p
354  * filp and add it into the double linked list in \p dev.
355  */
356 static int drm_open_helper(struct file *filp, struct drm_minor *minor)
357 {
358 	struct drm_device *dev = minor->dev;
359 	struct drm_file *priv;
360 	int ret;
361 
362 	if (filp->f_flags & O_EXCL)
363 		return -EBUSY;	/* No exclusive opens */
364 	if (!drm_cpu_valid())
365 		return -EINVAL;
366 	if (dev->switch_power_state != DRM_SWITCH_POWER_ON && dev->switch_power_state != DRM_SWITCH_POWER_DYNAMIC_OFF)
367 		return -EINVAL;
368 
369 	DRM_DEBUG("pid = %d, minor = %d\n", task_pid_nr(current), minor->index);
370 
371 	priv = drm_file_alloc(minor);
372 	if (IS_ERR(priv))
373 		return PTR_ERR(priv);
374 
375 	if (drm_is_primary_client(priv)) {
376 		ret = drm_master_open(priv);
377 		if (ret) {
378 			drm_file_free(priv);
379 			return ret;
380 		}
381 	}
382 
383 	filp->private_data = priv;
384 	filp->f_mode |= FMODE_UNSIGNED_OFFSET;
385 	priv->filp = filp;
386 
387 	mutex_lock(&dev->filelist_mutex);
388 	list_add(&priv->lhead, &dev->filelist);
389 	mutex_unlock(&dev->filelist_mutex);
390 
391 #ifdef __alpha__
392 	/*
393 	 * Default the hose
394 	 */
395 	if (!dev->hose) {
396 		struct pci_dev *pci_dev;
397 		pci_dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
398 		if (pci_dev) {
399 			dev->hose = pci_dev->sysdata;
400 			pci_dev_put(pci_dev);
401 		}
402 		if (!dev->hose) {
403 			struct pci_bus *b = list_entry(pci_root_buses.next,
404 				struct pci_bus, node);
405 			if (b)
406 				dev->hose = b->sysdata;
407 		}
408 	}
409 #endif
410 
411 	return 0;
412 }
413 
414 static void drm_legacy_dev_reinit(struct drm_device *dev)
415 {
416 	if (dev->irq_enabled)
417 		drm_irq_uninstall(dev);
418 
419 	mutex_lock(&dev->struct_mutex);
420 
421 	drm_legacy_agp_clear(dev);
422 
423 	drm_legacy_sg_cleanup(dev);
424 	drm_legacy_vma_flush(dev);
425 	drm_legacy_dma_takedown(dev);
426 
427 	mutex_unlock(&dev->struct_mutex);
428 
429 	dev->sigdata.lock = NULL;
430 
431 	dev->context_flag = 0;
432 	dev->last_context = 0;
433 	dev->if_version = 0;
434 
435 	DRM_DEBUG("lastclose completed\n");
436 }
437 
438 void drm_lastclose(struct drm_device * dev)
439 {
440 	DRM_DEBUG("\n");
441 
442 	if (dev->driver->lastclose)
443 		dev->driver->lastclose(dev);
444 	DRM_DEBUG("driver lastclose completed\n");
445 
446 	if (drm_core_check_feature(dev, DRIVER_LEGACY))
447 		drm_legacy_dev_reinit(dev);
448 
449 	drm_client_dev_restore(dev);
450 }
451 
452 /**
453  * drm_release - release method for DRM file
454  * @inode: device inode
455  * @filp: file pointer.
456  *
457  * This function must be used by drivers as their &file_operations.release
458  * method. It frees any resources associated with the open file, and calls the
459  * &drm_driver.postclose driver callback. If this is the last open file for the
460  * DRM device also proceeds to call the &drm_driver.lastclose driver callback.
461  *
462  * RETURNS:
463  *
464  * Always succeeds and returns 0.
465  */
466 int drm_release(struct inode *inode, struct file *filp)
467 {
468 	struct drm_file *file_priv = filp->private_data;
469 	struct drm_minor *minor = file_priv->minor;
470 	struct drm_device *dev = minor->dev;
471 
472 	mutex_lock(&drm_global_mutex);
473 
474 	DRM_DEBUG("open_count = %d\n", dev->open_count);
475 
476 	mutex_lock(&dev->filelist_mutex);
477 	list_del(&file_priv->lhead);
478 	mutex_unlock(&dev->filelist_mutex);
479 
480 	drm_file_free(file_priv);
481 
482 	if (!--dev->open_count) {
483 		drm_lastclose(dev);
484 		if (drm_dev_is_unplugged(dev))
485 			drm_put_dev(dev);
486 	}
487 	mutex_unlock(&drm_global_mutex);
488 
489 	drm_minor_release(minor);
490 
491 	return 0;
492 }
493 EXPORT_SYMBOL(drm_release);
494 
495 /**
496  * drm_read - read method for DRM file
497  * @filp: file pointer
498  * @buffer: userspace destination pointer for the read
499  * @count: count in bytes to read
500  * @offset: offset to read
501  *
502  * This function must be used by drivers as their &file_operations.read
503  * method iff they use DRM events for asynchronous signalling to userspace.
504  * Since events are used by the KMS API for vblank and page flip completion this
505  * means all modern display drivers must use it.
506  *
507  * @offset is ignored, DRM events are read like a pipe. Therefore drivers also
508  * must set the &file_operation.llseek to no_llseek(). Polling support is
509  * provided by drm_poll().
510  *
511  * This function will only ever read a full event. Therefore userspace must
512  * supply a big enough buffer to fit any event to ensure forward progress. Since
513  * the maximum event space is currently 4K it's recommended to just use that for
514  * safety.
515  *
516  * RETURNS:
517  *
518  * Number of bytes read (always aligned to full events, and can be 0) or a
519  * negative error code on failure.
520  */
521 ssize_t drm_read(struct file *filp, char __user *buffer,
522 		 size_t count, loff_t *offset)
523 {
524 	struct drm_file *file_priv = filp->private_data;
525 	struct drm_device *dev = file_priv->minor->dev;
526 	ssize_t ret;
527 
528 	if (!access_ok(buffer, count))
529 		return -EFAULT;
530 
531 	ret = mutex_lock_interruptible(&file_priv->event_read_lock);
532 	if (ret)
533 		return ret;
534 
535 	for (;;) {
536 		struct drm_pending_event *e = NULL;
537 
538 		spin_lock_irq(&dev->event_lock);
539 		if (!list_empty(&file_priv->event_list)) {
540 			e = list_first_entry(&file_priv->event_list,
541 					struct drm_pending_event, link);
542 			file_priv->event_space += e->event->length;
543 			list_del(&e->link);
544 		}
545 		spin_unlock_irq(&dev->event_lock);
546 
547 		if (e == NULL) {
548 			if (ret)
549 				break;
550 
551 			if (filp->f_flags & O_NONBLOCK) {
552 				ret = -EAGAIN;
553 				break;
554 			}
555 
556 			mutex_unlock(&file_priv->event_read_lock);
557 			ret = wait_event_interruptible(file_priv->event_wait,
558 						       !list_empty(&file_priv->event_list));
559 			if (ret >= 0)
560 				ret = mutex_lock_interruptible(&file_priv->event_read_lock);
561 			if (ret)
562 				return ret;
563 		} else {
564 			unsigned length = e->event->length;
565 
566 			if (length > count - ret) {
567 put_back_event:
568 				spin_lock_irq(&dev->event_lock);
569 				file_priv->event_space -= length;
570 				list_add(&e->link, &file_priv->event_list);
571 				spin_unlock_irq(&dev->event_lock);
572 				break;
573 			}
574 
575 			if (copy_to_user(buffer + ret, e->event, length)) {
576 				if (ret == 0)
577 					ret = -EFAULT;
578 				goto put_back_event;
579 			}
580 
581 			ret += length;
582 			kfree(e);
583 		}
584 	}
585 	mutex_unlock(&file_priv->event_read_lock);
586 
587 	return ret;
588 }
589 EXPORT_SYMBOL(drm_read);
590 
591 /**
592  * drm_poll - poll method for DRM file
593  * @filp: file pointer
594  * @wait: poll waiter table
595  *
596  * This function must be used by drivers as their &file_operations.read method
597  * iff they use DRM events for asynchronous signalling to userspace.  Since
598  * events are used by the KMS API for vblank and page flip completion this means
599  * all modern display drivers must use it.
600  *
601  * See also drm_read().
602  *
603  * RETURNS:
604  *
605  * Mask of POLL flags indicating the current status of the file.
606  */
607 __poll_t drm_poll(struct file *filp, struct poll_table_struct *wait)
608 {
609 	struct drm_file *file_priv = filp->private_data;
610 	__poll_t mask = 0;
611 
612 	poll_wait(filp, &file_priv->event_wait, wait);
613 
614 	if (!list_empty(&file_priv->event_list))
615 		mask |= EPOLLIN | EPOLLRDNORM;
616 
617 	return mask;
618 }
619 EXPORT_SYMBOL(drm_poll);
620 
621 /**
622  * drm_event_reserve_init_locked - init a DRM event and reserve space for it
623  * @dev: DRM device
624  * @file_priv: DRM file private data
625  * @p: tracking structure for the pending event
626  * @e: actual event data to deliver to userspace
627  *
628  * This function prepares the passed in event for eventual delivery. If the event
629  * doesn't get delivered (because the IOCTL fails later on, before queuing up
630  * anything) then the even must be cancelled and freed using
631  * drm_event_cancel_free(). Successfully initialized events should be sent out
632  * using drm_send_event() or drm_send_event_locked() to signal completion of the
633  * asynchronous event to userspace.
634  *
635  * If callers embedded @p into a larger structure it must be allocated with
636  * kmalloc and @p must be the first member element.
637  *
638  * This is the locked version of drm_event_reserve_init() for callers which
639  * already hold &drm_device.event_lock.
640  *
641  * RETURNS:
642  *
643  * 0 on success or a negative error code on failure.
644  */
645 int drm_event_reserve_init_locked(struct drm_device *dev,
646 				  struct drm_file *file_priv,
647 				  struct drm_pending_event *p,
648 				  struct drm_event *e)
649 {
650 	if (file_priv->event_space < e->length)
651 		return -ENOMEM;
652 
653 	file_priv->event_space -= e->length;
654 
655 	p->event = e;
656 	list_add(&p->pending_link, &file_priv->pending_event_list);
657 	p->file_priv = file_priv;
658 
659 	return 0;
660 }
661 EXPORT_SYMBOL(drm_event_reserve_init_locked);
662 
663 /**
664  * drm_event_reserve_init - init a DRM event and reserve space for it
665  * @dev: DRM device
666  * @file_priv: DRM file private data
667  * @p: tracking structure for the pending event
668  * @e: actual event data to deliver to userspace
669  *
670  * This function prepares the passed in event for eventual delivery. If the event
671  * doesn't get delivered (because the IOCTL fails later on, before queuing up
672  * anything) then the even must be cancelled and freed using
673  * drm_event_cancel_free(). Successfully initialized events should be sent out
674  * using drm_send_event() or drm_send_event_locked() to signal completion of the
675  * asynchronous event to userspace.
676  *
677  * If callers embedded @p into a larger structure it must be allocated with
678  * kmalloc and @p must be the first member element.
679  *
680  * Callers which already hold &drm_device.event_lock should use
681  * drm_event_reserve_init_locked() instead.
682  *
683  * RETURNS:
684  *
685  * 0 on success or a negative error code on failure.
686  */
687 int drm_event_reserve_init(struct drm_device *dev,
688 			   struct drm_file *file_priv,
689 			   struct drm_pending_event *p,
690 			   struct drm_event *e)
691 {
692 	unsigned long flags;
693 	int ret;
694 
695 	spin_lock_irqsave(&dev->event_lock, flags);
696 	ret = drm_event_reserve_init_locked(dev, file_priv, p, e);
697 	spin_unlock_irqrestore(&dev->event_lock, flags);
698 
699 	return ret;
700 }
701 EXPORT_SYMBOL(drm_event_reserve_init);
702 
703 /**
704  * drm_event_cancel_free - free a DRM event and release it's space
705  * @dev: DRM device
706  * @p: tracking structure for the pending event
707  *
708  * This function frees the event @p initialized with drm_event_reserve_init()
709  * and releases any allocated space. It is used to cancel an event when the
710  * nonblocking operation could not be submitted and needed to be aborted.
711  */
712 void drm_event_cancel_free(struct drm_device *dev,
713 			   struct drm_pending_event *p)
714 {
715 	unsigned long flags;
716 	spin_lock_irqsave(&dev->event_lock, flags);
717 	if (p->file_priv) {
718 		p->file_priv->event_space += p->event->length;
719 		list_del(&p->pending_link);
720 	}
721 	spin_unlock_irqrestore(&dev->event_lock, flags);
722 
723 	if (p->fence)
724 		dma_fence_put(p->fence);
725 
726 	kfree(p);
727 }
728 EXPORT_SYMBOL(drm_event_cancel_free);
729 
730 /**
731  * drm_send_event_locked - send DRM event to file descriptor
732  * @dev: DRM device
733  * @e: DRM event to deliver
734  *
735  * This function sends the event @e, initialized with drm_event_reserve_init(),
736  * to its associated userspace DRM file. Callers must already hold
737  * &drm_device.event_lock, see drm_send_event() for the unlocked version.
738  *
739  * Note that the core will take care of unlinking and disarming events when the
740  * corresponding DRM file is closed. Drivers need not worry about whether the
741  * DRM file for this event still exists and can call this function upon
742  * completion of the asynchronous work unconditionally.
743  */
744 void drm_send_event_locked(struct drm_device *dev, struct drm_pending_event *e)
745 {
746 	assert_spin_locked(&dev->event_lock);
747 
748 	if (e->completion) {
749 		complete_all(e->completion);
750 		e->completion_release(e->completion);
751 		e->completion = NULL;
752 	}
753 
754 	if (e->fence) {
755 		dma_fence_signal(e->fence);
756 		dma_fence_put(e->fence);
757 	}
758 
759 	if (!e->file_priv) {
760 		kfree(e);
761 		return;
762 	}
763 
764 	list_del(&e->pending_link);
765 	list_add_tail(&e->link,
766 		      &e->file_priv->event_list);
767 	wake_up_interruptible(&e->file_priv->event_wait);
768 }
769 EXPORT_SYMBOL(drm_send_event_locked);
770 
771 /**
772  * drm_send_event - send DRM event to file descriptor
773  * @dev: DRM device
774  * @e: DRM event to deliver
775  *
776  * This function sends the event @e, initialized with drm_event_reserve_init(),
777  * to its associated userspace DRM file. This function acquires
778  * &drm_device.event_lock, see drm_send_event_locked() for callers which already
779  * hold this lock.
780  *
781  * Note that the core will take care of unlinking and disarming events when the
782  * corresponding DRM file is closed. Drivers need not worry about whether the
783  * DRM file for this event still exists and can call this function upon
784  * completion of the asynchronous work unconditionally.
785  */
786 void drm_send_event(struct drm_device *dev, struct drm_pending_event *e)
787 {
788 	unsigned long irqflags;
789 
790 	spin_lock_irqsave(&dev->event_lock, irqflags);
791 	drm_send_event_locked(dev, e);
792 	spin_unlock_irqrestore(&dev->event_lock, irqflags);
793 }
794 EXPORT_SYMBOL(drm_send_event);
795