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