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