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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/dma-fence.h>
35 #include <linux/module.h>
36 #include <linux/pci.h>
37 #include <linux/poll.h>
38 #include <linux/slab.h>
39 
40 #include <drm/drm_client.h>
41 #include <drm/drm_drv.h>
42 #include <drm/drm_file.h>
43 #include <drm/drm_print.h>
44 
45 #include "drm_crtc_internal.h"
46 #include "drm_internal.h"
47 #include "drm_legacy.h"
48 
49 /* from BKL pushdown */
50 DEFINE_MUTEX(drm_global_mutex);
51 
52 #define MAX_DRM_OPEN_COUNT		128
53 
54 /**
55  * DOC: file operations
56  *
57  * Drivers must define the file operations structure that forms the DRM
58  * userspace API entry point, even though most of those operations are
59  * implemented in the DRM core. The resulting &struct file_operations must be
60  * stored in the &drm_driver.fops field. The mandatory functions are drm_open(),
61  * drm_read(), drm_ioctl() and drm_compat_ioctl() if CONFIG_COMPAT is enabled
62  * Note that drm_compat_ioctl will be NULL if CONFIG_COMPAT=n, so there's no
63  * need to sprinkle #ifdef into the code. Drivers which implement private ioctls
64  * that require 32/64 bit compatibility support must provide their own
65  * &file_operations.compat_ioctl handler that processes private ioctls and calls
66  * drm_compat_ioctl() for core ioctls.
67  *
68  * In addition drm_read() and drm_poll() provide support for DRM events. DRM
69  * events are a generic and extensible means to send asynchronous events to
70  * userspace through the file descriptor. They are used to send vblank event and
71  * page flip completions by the KMS API. But drivers can also use it for their
72  * own needs, e.g. to signal completion of rendering.
73  *
74  * For the driver-side event interface see drm_event_reserve_init() and
75  * drm_send_event() as the main starting points.
76  *
77  * The memory mapping implementation will vary depending on how the driver
78  * manages memory. Legacy drivers will use the deprecated drm_legacy_mmap()
79  * function, modern drivers should use one of the provided memory-manager
80  * specific implementations. For GEM-based drivers this is drm_gem_mmap(), and
81  * for drivers which use the CMA GEM helpers it's drm_gem_cma_mmap().
82  *
83  * No other file operations are supported by the DRM userspace API. Overall the
84  * following is an example &file_operations structure::
85  *
86  *     static const example_drm_fops = {
87  *             .owner = THIS_MODULE,
88  *             .open = drm_open,
89  *             .release = drm_release,
90  *             .unlocked_ioctl = drm_ioctl,
91  *             .compat_ioctl = drm_compat_ioctl, // NULL if CONFIG_COMPAT=n
92  *             .poll = drm_poll,
93  *             .read = drm_read,
94  *             .llseek = no_llseek,
95  *             .mmap = drm_gem_mmap,
96  *     };
97  *
98  * For plain GEM based drivers there is the DEFINE_DRM_GEM_FOPS() macro, and for
99  * CMA based drivers there is the DEFINE_DRM_GEM_CMA_FOPS() macro to make this
100  * simpler.
101  *
102  * The driver's &file_operations must be stored in &drm_driver.fops.
103  *
104  * For driver-private IOCTL handling see the more detailed discussion in
105  * :ref:`IOCTL support in the userland interfaces chapter<drm_driver_ioctl>`.
106  */
107 
108 /**
109  * drm_file_alloc - allocate file context
110  * @minor: minor to allocate on
111  *
112  * This allocates a new DRM file context. It is not linked into any context and
113  * can be used by the caller freely. Note that the context keeps a pointer to
114  * @minor, so it must be freed before @minor is.
115  *
116  * RETURNS:
117  * Pointer to newly allocated context, ERR_PTR on failure.
118  */
drm_file_alloc(struct drm_minor * minor)119 struct drm_file *drm_file_alloc(struct drm_minor *minor)
120 {
121 	struct drm_device *dev = minor->dev;
122 	struct drm_file *file;
123 	int ret;
124 
125 	file = kzalloc(sizeof(*file), GFP_KERNEL);
126 	if (!file)
127 		return ERR_PTR(-ENOMEM);
128 
129 	file->pid = get_pid(task_pid(current));
130 	file->minor = minor;
131 
132 	/* for compatibility root is always authenticated */
133 	file->authenticated = capable(CAP_SYS_ADMIN);
134 
135 	INIT_LIST_HEAD(&file->lhead);
136 	INIT_LIST_HEAD(&file->fbs);
137 	mutex_init(&file->fbs_lock);
138 	INIT_LIST_HEAD(&file->blobs);
139 	INIT_LIST_HEAD(&file->pending_event_list);
140 	INIT_LIST_HEAD(&file->event_list);
141 	init_waitqueue_head(&file->event_wait);
142 	file->event_space = 4096; /* set aside 4k for event buffer */
143 
144 	mutex_init(&file->event_read_lock);
145 
146 	if (drm_core_check_feature(dev, DRIVER_GEM))
147 		drm_gem_open(dev, file);
148 
149 	if (drm_core_check_feature(dev, DRIVER_SYNCOBJ))
150 		drm_syncobj_open(file);
151 
152 	drm_prime_init_file_private(&file->prime);
153 
154 	if (dev->driver->open) {
155 		ret = dev->driver->open(dev, file);
156 		if (ret < 0)
157 			goto out_prime_destroy;
158 	}
159 
160 	return file;
161 
162 out_prime_destroy:
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 
drm_events_release(struct drm_file * file_priv)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  */
drm_file_free(struct drm_file * file)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 	drm_prime_destroy_file_private(&file->prime);
257 
258 	WARN_ON(!list_empty(&file->event_list));
259 
260 	put_pid(file->pid);
261 	kfree(file);
262 }
263 
drm_close_helper(struct file * filp)264 static void drm_close_helper(struct file *filp)
265 {
266 	struct drm_file *file_priv = filp->private_data;
267 	struct drm_device *dev = file_priv->minor->dev;
268 
269 	mutex_lock(&dev->filelist_mutex);
270 	list_del(&file_priv->lhead);
271 	mutex_unlock(&dev->filelist_mutex);
272 
273 	drm_file_free(file_priv);
274 }
275 
276 /*
277  * Check whether DRI will run on this CPU.
278  *
279  * \return non-zero if the DRI will run on this CPU, or zero otherwise.
280  */
drm_cpu_valid(void)281 static int drm_cpu_valid(void)
282 {
283 #if defined(__sparc__) && !defined(__sparc_v9__)
284 	return 0;		/* No cmpxchg before v9 sparc. */
285 #endif
286 	return 1;
287 }
288 
289 /*
290  * Called whenever a process opens /dev/drm.
291  *
292  * \param filp file pointer.
293  * \param minor acquired minor-object.
294  * \return zero on success or a negative number on failure.
295  *
296  * Creates and initializes a drm_file structure for the file private data in \p
297  * filp and add it into the double linked list in \p dev.
298  */
drm_open_helper(struct file * filp,struct drm_minor * minor)299 static int drm_open_helper(struct file *filp, struct drm_minor *minor)
300 {
301 	struct drm_device *dev = minor->dev;
302 	struct drm_file *priv;
303 	int ret;
304 
305 	if (filp->f_flags & O_EXCL)
306 		return -EBUSY;	/* No exclusive opens */
307 	if (!drm_cpu_valid())
308 		return -EINVAL;
309 	if (dev->switch_power_state != DRM_SWITCH_POWER_ON && dev->switch_power_state != DRM_SWITCH_POWER_DYNAMIC_OFF)
310 		return -EINVAL;
311 
312 	DRM_DEBUG("pid = %d, minor = %d\n", task_pid_nr(current), minor->index);
313 
314 	priv = drm_file_alloc(minor);
315 	if (IS_ERR(priv))
316 		return PTR_ERR(priv);
317 
318 	if (drm_is_primary_client(priv)) {
319 		ret = drm_master_open(priv);
320 		if (ret) {
321 			drm_file_free(priv);
322 			return ret;
323 		}
324 	}
325 
326 	filp->private_data = priv;
327 	filp->f_mode |= FMODE_UNSIGNED_OFFSET;
328 	priv->filp = filp;
329 
330 	mutex_lock(&dev->filelist_mutex);
331 	list_add(&priv->lhead, &dev->filelist);
332 	mutex_unlock(&dev->filelist_mutex);
333 
334 #ifdef __alpha__
335 	/*
336 	 * Default the hose
337 	 */
338 	if (!dev->hose) {
339 		struct pci_dev *pci_dev;
340 		pci_dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
341 		if (pci_dev) {
342 			dev->hose = pci_dev->sysdata;
343 			pci_dev_put(pci_dev);
344 		}
345 		if (!dev->hose) {
346 			struct pci_bus *b = list_entry(pci_root_buses.next,
347 				struct pci_bus, node);
348 			if (b)
349 				dev->hose = b->sysdata;
350 		}
351 	}
352 #endif
353 
354 	return 0;
355 }
356 
357 /**
358  * drm_open - open method for DRM file
359  * @inode: device inode
360  * @filp: file pointer.
361  *
362  * This function must be used by drivers as their &file_operations.open method.
363  * It looks up the correct DRM device and instantiates all the per-file
364  * resources for it. It also calls the &drm_driver.open driver callback.
365  *
366  * RETURNS:
367  *
368  * 0 on success or negative errno value on falure.
369  */
drm_open(struct inode * inode,struct file * filp)370 int drm_open(struct inode *inode, struct file *filp)
371 {
372 	struct drm_device *dev;
373 	struct drm_minor *minor;
374 	int retcode;
375 	int need_setup = 0;
376 
377 	minor = drm_minor_acquire(iminor(inode));
378 	if (IS_ERR(minor))
379 		return PTR_ERR(minor);
380 
381 	dev = minor->dev;
382 	if (!dev->open_count++)
383 		need_setup = 1;
384 
385 	if (dev->open_count >= MAX_DRM_OPEN_COUNT) {
386 		retcode = -EPERM;
387 		goto err_undo;
388 	}
389 
390 	/* share address_space across all char-devs of a single device */
391 	filp->f_mapping = dev->anon_inode->i_mapping;
392 
393 	retcode = drm_open_helper(filp, minor);
394 	if (retcode)
395 		goto err_undo;
396 	if (need_setup) {
397 		retcode = drm_legacy_setup(dev);
398 		if (retcode) {
399 			drm_close_helper(filp);
400 			goto err_undo;
401 		}
402 	}
403 	return 0;
404 
405 err_undo:
406 	dev->open_count--;
407 	drm_minor_release(minor);
408 	return retcode;
409 }
410 EXPORT_SYMBOL(drm_open);
411 
drm_lastclose(struct drm_device * dev)412 void drm_lastclose(struct drm_device * dev)
413 {
414 	DRM_DEBUG("\n");
415 
416 	if (dev->driver->lastclose)
417 		dev->driver->lastclose(dev);
418 	DRM_DEBUG("driver lastclose completed\n");
419 
420 	if (drm_core_check_feature(dev, DRIVER_LEGACY))
421 		drm_legacy_dev_reinit(dev);
422 
423 	drm_client_dev_restore(dev);
424 }
425 
426 /**
427  * drm_release - release method for DRM file
428  * @inode: device inode
429  * @filp: file pointer.
430  *
431  * This function must be used by drivers as their &file_operations.release
432  * method. It frees any resources associated with the open file, and calls the
433  * &drm_driver.postclose driver callback. If this is the last open file for the
434  * DRM device also proceeds to call the &drm_driver.lastclose driver callback.
435  *
436  * RETURNS:
437  *
438  * Always succeeds and returns 0.
439  */
drm_release(struct inode * inode,struct file * filp)440 int drm_release(struct inode *inode, struct file *filp)
441 {
442 	struct drm_file *file_priv = filp->private_data;
443 	struct drm_minor *minor = file_priv->minor;
444 	struct drm_device *dev = minor->dev;
445 
446 	mutex_lock(&drm_global_mutex);
447 
448 	DRM_DEBUG("open_count = %d\n", dev->open_count);
449 
450 	drm_close_helper(filp);
451 
452 	if (!--dev->open_count)
453 		drm_lastclose(dev);
454 
455 	mutex_unlock(&drm_global_mutex);
456 
457 	drm_minor_release(minor);
458 
459 	return 0;
460 }
461 EXPORT_SYMBOL(drm_release);
462 
463 /**
464  * drm_read - read method for DRM file
465  * @filp: file pointer
466  * @buffer: userspace destination pointer for the read
467  * @count: count in bytes to read
468  * @offset: offset to read
469  *
470  * This function must be used by drivers as their &file_operations.read
471  * method iff they use DRM events for asynchronous signalling to userspace.
472  * Since events are used by the KMS API for vblank and page flip completion this
473  * means all modern display drivers must use it.
474  *
475  * @offset is ignored, DRM events are read like a pipe. Therefore drivers also
476  * must set the &file_operation.llseek to no_llseek(). Polling support is
477  * provided by drm_poll().
478  *
479  * This function will only ever read a full event. Therefore userspace must
480  * supply a big enough buffer to fit any event to ensure forward progress. Since
481  * the maximum event space is currently 4K it's recommended to just use that for
482  * safety.
483  *
484  * RETURNS:
485  *
486  * Number of bytes read (always aligned to full events, and can be 0) or a
487  * negative error code on failure.
488  */
drm_read(struct file * filp,char __user * buffer,size_t count,loff_t * offset)489 ssize_t drm_read(struct file *filp, char __user *buffer,
490 		 size_t count, loff_t *offset)
491 {
492 	struct drm_file *file_priv = filp->private_data;
493 	struct drm_device *dev = file_priv->minor->dev;
494 	ssize_t ret;
495 
496 	if (!access_ok(buffer, count))
497 		return -EFAULT;
498 
499 	ret = mutex_lock_interruptible(&file_priv->event_read_lock);
500 	if (ret)
501 		return ret;
502 
503 	for (;;) {
504 		struct drm_pending_event *e = NULL;
505 
506 		spin_lock_irq(&dev->event_lock);
507 		if (!list_empty(&file_priv->event_list)) {
508 			e = list_first_entry(&file_priv->event_list,
509 					struct drm_pending_event, link);
510 			file_priv->event_space += e->event->length;
511 			list_del(&e->link);
512 		}
513 		spin_unlock_irq(&dev->event_lock);
514 
515 		if (e == NULL) {
516 			if (ret)
517 				break;
518 
519 			if (filp->f_flags & O_NONBLOCK) {
520 				ret = -EAGAIN;
521 				break;
522 			}
523 
524 			mutex_unlock(&file_priv->event_read_lock);
525 			ret = wait_event_interruptible(file_priv->event_wait,
526 						       !list_empty(&file_priv->event_list));
527 			if (ret >= 0)
528 				ret = mutex_lock_interruptible(&file_priv->event_read_lock);
529 			if (ret)
530 				return ret;
531 		} else {
532 			unsigned length = e->event->length;
533 
534 			if (length > count - ret) {
535 put_back_event:
536 				spin_lock_irq(&dev->event_lock);
537 				file_priv->event_space -= length;
538 				list_add(&e->link, &file_priv->event_list);
539 				spin_unlock_irq(&dev->event_lock);
540 				wake_up_interruptible(&file_priv->event_wait);
541 				break;
542 			}
543 
544 			if (copy_to_user(buffer + ret, e->event, length)) {
545 				if (ret == 0)
546 					ret = -EFAULT;
547 				goto put_back_event;
548 			}
549 
550 			ret += length;
551 			kfree(e);
552 		}
553 	}
554 	mutex_unlock(&file_priv->event_read_lock);
555 
556 	return ret;
557 }
558 EXPORT_SYMBOL(drm_read);
559 
560 /**
561  * drm_poll - poll method for DRM file
562  * @filp: file pointer
563  * @wait: poll waiter table
564  *
565  * This function must be used by drivers as their &file_operations.read method
566  * iff they use DRM events for asynchronous signalling to userspace.  Since
567  * events are used by the KMS API for vblank and page flip completion this means
568  * all modern display drivers must use it.
569  *
570  * See also drm_read().
571  *
572  * RETURNS:
573  *
574  * Mask of POLL flags indicating the current status of the file.
575  */
drm_poll(struct file * filp,struct poll_table_struct * wait)576 __poll_t drm_poll(struct file *filp, struct poll_table_struct *wait)
577 {
578 	struct drm_file *file_priv = filp->private_data;
579 	__poll_t mask = 0;
580 
581 	poll_wait(filp, &file_priv->event_wait, wait);
582 
583 	if (!list_empty(&file_priv->event_list))
584 		mask |= EPOLLIN | EPOLLRDNORM;
585 
586 	return mask;
587 }
588 EXPORT_SYMBOL(drm_poll);
589 
590 /**
591  * drm_event_reserve_init_locked - init a DRM event and reserve space for it
592  * @dev: DRM device
593  * @file_priv: DRM file private data
594  * @p: tracking structure for the pending event
595  * @e: actual event data to deliver to userspace
596  *
597  * This function prepares the passed in event for eventual delivery. If the event
598  * doesn't get delivered (because the IOCTL fails later on, before queuing up
599  * anything) then the even must be cancelled and freed using
600  * drm_event_cancel_free(). Successfully initialized events should be sent out
601  * using drm_send_event() or drm_send_event_locked() to signal completion of the
602  * asynchronous event to userspace.
603  *
604  * If callers embedded @p into a larger structure it must be allocated with
605  * kmalloc and @p must be the first member element.
606  *
607  * This is the locked version of drm_event_reserve_init() for callers which
608  * already hold &drm_device.event_lock.
609  *
610  * RETURNS:
611  *
612  * 0 on success or a negative error code on failure.
613  */
drm_event_reserve_init_locked(struct drm_device * dev,struct drm_file * file_priv,struct drm_pending_event * p,struct drm_event * e)614 int drm_event_reserve_init_locked(struct drm_device *dev,
615 				  struct drm_file *file_priv,
616 				  struct drm_pending_event *p,
617 				  struct drm_event *e)
618 {
619 	if (file_priv->event_space < e->length)
620 		return -ENOMEM;
621 
622 	file_priv->event_space -= e->length;
623 
624 	p->event = e;
625 	list_add(&p->pending_link, &file_priv->pending_event_list);
626 	p->file_priv = file_priv;
627 
628 	return 0;
629 }
630 EXPORT_SYMBOL(drm_event_reserve_init_locked);
631 
632 /**
633  * drm_event_reserve_init - init a DRM event and reserve space for it
634  * @dev: DRM device
635  * @file_priv: DRM file private data
636  * @p: tracking structure for the pending event
637  * @e: actual event data to deliver to userspace
638  *
639  * This function prepares the passed in event for eventual delivery. If the event
640  * doesn't get delivered (because the IOCTL fails later on, before queuing up
641  * anything) then the even must be cancelled and freed using
642  * drm_event_cancel_free(). Successfully initialized events should be sent out
643  * using drm_send_event() or drm_send_event_locked() to signal completion of the
644  * asynchronous event to userspace.
645  *
646  * If callers embedded @p into a larger structure it must be allocated with
647  * kmalloc and @p must be the first member element.
648  *
649  * Callers which already hold &drm_device.event_lock should use
650  * drm_event_reserve_init_locked() instead.
651  *
652  * RETURNS:
653  *
654  * 0 on success or a negative error code on failure.
655  */
drm_event_reserve_init(struct drm_device * dev,struct drm_file * file_priv,struct drm_pending_event * p,struct drm_event * e)656 int drm_event_reserve_init(struct drm_device *dev,
657 			   struct drm_file *file_priv,
658 			   struct drm_pending_event *p,
659 			   struct drm_event *e)
660 {
661 	unsigned long flags;
662 	int ret;
663 
664 	spin_lock_irqsave(&dev->event_lock, flags);
665 	ret = drm_event_reserve_init_locked(dev, file_priv, p, e);
666 	spin_unlock_irqrestore(&dev->event_lock, flags);
667 
668 	return ret;
669 }
670 EXPORT_SYMBOL(drm_event_reserve_init);
671 
672 /**
673  * drm_event_cancel_free - free a DRM event and release its space
674  * @dev: DRM device
675  * @p: tracking structure for the pending event
676  *
677  * This function frees the event @p initialized with drm_event_reserve_init()
678  * and releases any allocated space. It is used to cancel an event when the
679  * nonblocking operation could not be submitted and needed to be aborted.
680  */
drm_event_cancel_free(struct drm_device * dev,struct drm_pending_event * p)681 void drm_event_cancel_free(struct drm_device *dev,
682 			   struct drm_pending_event *p)
683 {
684 	unsigned long flags;
685 	spin_lock_irqsave(&dev->event_lock, flags);
686 	if (p->file_priv) {
687 		p->file_priv->event_space += p->event->length;
688 		list_del(&p->pending_link);
689 	}
690 	spin_unlock_irqrestore(&dev->event_lock, flags);
691 
692 	if (p->fence)
693 		dma_fence_put(p->fence);
694 
695 	kfree(p);
696 }
697 EXPORT_SYMBOL(drm_event_cancel_free);
698 
699 /**
700  * drm_send_event_locked - send DRM event to file descriptor
701  * @dev: DRM device
702  * @e: DRM event to deliver
703  *
704  * This function sends the event @e, initialized with drm_event_reserve_init(),
705  * to its associated userspace DRM file. Callers must already hold
706  * &drm_device.event_lock, see drm_send_event() for the unlocked version.
707  *
708  * Note that the core will take care of unlinking and disarming events when the
709  * corresponding DRM file is closed. Drivers need not worry about whether the
710  * DRM file for this event still exists and can call this function upon
711  * completion of the asynchronous work unconditionally.
712  */
drm_send_event_locked(struct drm_device * dev,struct drm_pending_event * e)713 void drm_send_event_locked(struct drm_device *dev, struct drm_pending_event *e)
714 {
715 	assert_spin_locked(&dev->event_lock);
716 
717 	if (e->completion) {
718 		complete_all(e->completion);
719 		e->completion_release(e->completion);
720 		e->completion = NULL;
721 	}
722 
723 	if (e->fence) {
724 		dma_fence_signal(e->fence);
725 		dma_fence_put(e->fence);
726 	}
727 
728 	if (!e->file_priv) {
729 		kfree(e);
730 		return;
731 	}
732 
733 	list_del(&e->pending_link);
734 	list_add_tail(&e->link,
735 		      &e->file_priv->event_list);
736 	wake_up_interruptible(&e->file_priv->event_wait);
737 }
738 EXPORT_SYMBOL(drm_send_event_locked);
739 
740 /**
741  * drm_send_event - send DRM event to file descriptor
742  * @dev: DRM device
743  * @e: DRM event to deliver
744  *
745  * This function sends the event @e, initialized with drm_event_reserve_init(),
746  * to its associated userspace DRM file. This function acquires
747  * &drm_device.event_lock, see drm_send_event_locked() for callers which already
748  * hold this lock.
749  *
750  * Note that the core will take care of unlinking and disarming events when the
751  * corresponding DRM file is closed. Drivers need not worry about whether the
752  * DRM file for this event still exists and can call this function upon
753  * completion of the asynchronous work unconditionally.
754  */
drm_send_event(struct drm_device * dev,struct drm_pending_event * e)755 void drm_send_event(struct drm_device *dev, struct drm_pending_event *e)
756 {
757 	unsigned long irqflags;
758 
759 	spin_lock_irqsave(&dev->event_lock, irqflags);
760 	drm_send_event_locked(dev, e);
761 	spin_unlock_irqrestore(&dev->event_lock, irqflags);
762 }
763 EXPORT_SYMBOL(drm_send_event);
764