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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
44/* from BKL pushdown */
45DEFINE_MUTEX(drm_global_mutex);
46
47/**
48 * DOC: file operations
49 *
50 * Drivers must define the file operations structure that forms the DRM
51 * userspace API entry point, even though most of those operations are
52 * implemented in the DRM core. The mandatory functions are drm_open(),
53 * drm_read(), drm_ioctl() and drm_compat_ioctl if CONFIG_COMPAT is enabled.
54 * Drivers which implement private ioctls that require 32/64 bit compatibility
55 * support must provided their onw .compat_ioctl() handler that processes
56 * private ioctls and calls drm_compat_ioctl() for core ioctls.
57 *
58 * In addition drm_read() and drm_poll() provide support for DRM events. DRM
59 * events are a generic and extensible means to send asynchronous events to
60 * userspace through the file descriptor. They are used to send vblank event and
61 * page flip completions by the KMS API. But drivers can also use it for their
62 * own needs, e.g. to signal completion of rendering.
63 *
64 * The memory mapping implementation will vary depending on how the driver
65 * manages memory. Legacy drivers will use the deprecated drm_legacy_mmap()
66 * function, modern drivers should use one of the provided memory-manager
67 * specific implementations. For GEM-based drivers this is drm_gem_mmap().
68 *
69 * No other file operations are supported by the DRM userspace API. Overall the
70 * following is an example #file_operations structure:
71 *
72 * static const example_drm_fops = {
73 * .owner = THIS_MODULE,
74 * .open = drm_open,
75 * .release = drm_release,
76 * .unlocked_ioctl = drm_ioctl,
77 * #ifdef CONFIG_COMPAT
78 * .compat_ioctl = drm_compat_ioctl,
79 * #endif
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_MODESET)) {
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 * drm_new_set_master - Allocate a new master object and become master for the
172 * associated master realm.
173 *
174 * @dev: The associated device.
175 * @fpriv: File private identifying the client.
176 *
177 * This function must be called with dev::struct_mutex held.
178 * Returns negative error code on failure. Zero on success.
179 */
180int drm_new_set_master(struct drm_device *dev, struct drm_file *fpriv)
181{
182 struct drm_master *old_master;
183 int ret;
184
185 lockdep_assert_held_once(&dev->master_mutex);
186
187 /* create a new master */
188 fpriv->minor->master = drm_master_create(fpriv->minor);
189 if (!fpriv->minor->master)
190 return -ENOMEM;
191
192 /* take another reference for the copy in the local file priv */
193 old_master = fpriv->master;
194 fpriv->master = drm_master_get(fpriv->minor->master);
195
196 if (dev->driver->master_create) {
197 ret = dev->driver->master_create(dev, fpriv->master);
198 if (ret)
199 goto out_err;
200 }
201 if (dev->driver->master_set) {
202 ret = dev->driver->master_set(dev, fpriv, true);
203 if (ret)
204 goto out_err;
205 }
206
207 fpriv->is_master = 1;
208 fpriv->allowed_master = 1;
209 fpriv->authenticated = 1;
210 if (old_master)
211 drm_master_put(&old_master);
212
213 return 0;
214
215out_err:
216 /* drop both references and restore old master on failure */
217 drm_master_put(&fpriv->minor->master);
218 drm_master_put(&fpriv->master);
219 fpriv->master = old_master;
220
221 return ret;
222}
223
224/*
225 * Called whenever a process opens /dev/drm.
226 *
227 * \param filp file pointer.
228 * \param minor acquired minor-object.
229 * \return zero on success or a negative number on failure.
230 *
231 * Creates and initializes a drm_file structure for the file private data in \p
232 * filp and add it into the double linked list in \p dev.
233 */
234static int drm_open_helper(struct file *filp, struct drm_minor *minor)
235{
236 struct drm_device *dev = minor->dev;
237 struct drm_file *priv;
238 int ret;
239
240 if (filp->f_flags & O_EXCL)
241 return -EBUSY; /* No exclusive opens */
242 if (!drm_cpu_valid())
243 return -EINVAL;
244 if (dev->switch_power_state != DRM_SWITCH_POWER_ON && dev->switch_power_state != DRM_SWITCH_POWER_DYNAMIC_OFF)
245 return -EINVAL;
246
247 DRM_DEBUG("pid = %d, minor = %d\n", task_pid_nr(current), minor->index);
248
249 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
250 if (!priv)
251 return -ENOMEM;
252
253 filp->private_data = priv;
254 priv->filp = filp;
255 priv->uid = current_euid();
256 priv->pid = get_pid(task_pid(current));
257 priv->minor = minor;
258
259 /* for compatibility root is always authenticated */
260 priv->authenticated = capable(CAP_SYS_ADMIN);
261 priv->lock_count = 0;
262
263 INIT_LIST_HEAD(&priv->lhead);
264 INIT_LIST_HEAD(&priv->fbs);
265 mutex_init(&priv->fbs_lock);
266 INIT_LIST_HEAD(&priv->blobs);
267 INIT_LIST_HEAD(&priv->pending_event_list);
268 INIT_LIST_HEAD(&priv->event_list);
269 init_waitqueue_head(&priv->event_wait);
270 priv->event_space = 4096; /* set aside 4k for event buffer */
271
272 mutex_init(&priv->event_read_lock);
273
274 if (drm_core_check_feature(dev, DRIVER_GEM))
275 drm_gem_open(dev, priv);
276
277 if (drm_core_check_feature(dev, DRIVER_PRIME))
278 drm_prime_init_file_private(&priv->prime);
279
280 if (dev->driver->open) {
281 ret = dev->driver->open(dev, priv);
282 if (ret < 0)
283 goto out_prime_destroy;
284 }
285
286 /* if there is no current master make this fd it, but do not create
287 * any master object for render clients */
288 mutex_lock(&dev->master_mutex);
289 if (drm_is_primary_client(priv) && !priv->minor->master) {
290 /* create a new master */
291 ret = drm_new_set_master(dev, priv);
292 if (ret)
293 goto out_close;
294 } else if (drm_is_primary_client(priv)) {
295 /* get a reference to the master */
296 priv->master = drm_master_get(priv->minor->master);
297 }
298 mutex_unlock(&dev->master_mutex);
299
300 mutex_lock(&dev->struct_mutex);
301 list_add(&priv->lhead, &dev->filelist);
302 mutex_unlock(&dev->struct_mutex);
303
304#ifdef __alpha__
305 /*
306 * Default the hose
307 */
308 if (!dev->hose) {
309 struct pci_dev *pci_dev;
310 pci_dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
311 if (pci_dev) {
312 dev->hose = pci_dev->sysdata;
313 pci_dev_put(pci_dev);
314 }
315 if (!dev->hose) {
316 struct pci_bus *b = list_entry(pci_root_buses.next,
317 struct pci_bus, node);
318 if (b)
319 dev->hose = b->sysdata;
320 }
321 }
322#endif
323
324 return 0;
325
326out_close:
327 mutex_unlock(&dev->master_mutex);
328 if (dev->driver->postclose)
329 dev->driver->postclose(dev, priv);
330out_prime_destroy:
331 if (drm_core_check_feature(dev, DRIVER_PRIME))
332 drm_prime_destroy_file_private(&priv->prime);
333 if (drm_core_check_feature(dev, DRIVER_GEM))
334 drm_gem_release(dev, priv);
335 put_pid(priv->pid);
336 kfree(priv);
337 filp->private_data = NULL;
338 return ret;
339}
340
341static void drm_master_release(struct drm_device *dev, struct file *filp)
342{
343 struct drm_file *file_priv = filp->private_data;
344
345 if (drm_legacy_i_have_hw_lock(dev, file_priv)) {
346 DRM_DEBUG("File %p released, freeing lock for context %d\n",
347 filp, _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
348 drm_legacy_lock_free(&file_priv->master->lock,
349 _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
350 }
351}
352
353static void drm_events_release(struct drm_file *file_priv)
354{
355 struct drm_device *dev = file_priv->minor->dev;
356 struct drm_pending_event *e, *et;
357 unsigned long flags;
358
359 spin_lock_irqsave(&dev->event_lock, flags);
360
361 /* Unlink pending events */
362 list_for_each_entry_safe(e, et, &file_priv->pending_event_list,
363 pending_link) {
364 list_del(&e->pending_link);
365 e->file_priv = NULL;
366 }
367
368 /* Remove unconsumed events */
369 list_for_each_entry_safe(e, et, &file_priv->event_list, link) {
370 list_del(&e->link);
371 e->destroy(e);
372 }
373
374 spin_unlock_irqrestore(&dev->event_lock, flags);
375}
376
377/*
378 * drm_legacy_dev_reinit
379 *
380 * Reinitializes a legacy/ums drm device in it's lastclose function.
381 */
382static void drm_legacy_dev_reinit(struct drm_device *dev)
383{
384 if (drm_core_check_feature(dev, DRIVER_MODESET))
385 return;
386
387 dev->sigdata.lock = NULL;
388
389 dev->context_flag = 0;
390 dev->last_context = 0;
391 dev->if_version = 0;
392}
393
394/*
395 * Take down the DRM device.
396 *
397 * \param dev DRM device structure.
398 *
399 * Frees every resource in \p dev.
400 *
401 * \sa drm_device
402 */
403int drm_lastclose(struct drm_device * dev)
404{
405 DRM_DEBUG("\n");
406
407 if (dev->driver->lastclose)
408 dev->driver->lastclose(dev);
409 DRM_DEBUG("driver lastclose completed\n");
410
411 if (dev->irq_enabled && !drm_core_check_feature(dev, DRIVER_MODESET))
412 drm_irq_uninstall(dev);
413
414 mutex_lock(&dev->struct_mutex);
415
416 drm_agp_clear(dev);
417
418 drm_legacy_sg_cleanup(dev);
419 drm_legacy_vma_flush(dev);
420 drm_legacy_dma_takedown(dev);
421
422 mutex_unlock(&dev->struct_mutex);
423
424 drm_legacy_dev_reinit(dev);
425
426 DRM_DEBUG("lastclose completed\n");
427 return 0;
428}
429
430/**
431 * drm_release - release method for DRM file
432 * @inode: device inode
433 * @filp: file pointer.
434 *
435 * This function must be used by drivers as their .release() #file_operations
436 * method. It frees any resources associated with the open file, and if this is
437 * the last open file for the DRM device also proceeds to call drm_lastclose().
438 *
439 * RETURNS:
440 *
441 * Always succeeds and returns 0.
442 */
443int drm_release(struct inode *inode, struct file *filp)
444{
445 struct drm_file *file_priv = filp->private_data;
446 struct drm_minor *minor = file_priv->minor;
447 struct drm_device *dev = minor->dev;
448 int retcode = 0;
449
450 mutex_lock(&drm_global_mutex);
451
452 DRM_DEBUG("open_count = %d\n", dev->open_count);
453
454 mutex_lock(&dev->struct_mutex);
455 list_del(&file_priv->lhead);
456 if (file_priv->magic)
457 idr_remove(&file_priv->master->magic_map, file_priv->magic);
458 mutex_unlock(&dev->struct_mutex);
459
460 if (dev->driver->preclose)
461 dev->driver->preclose(dev, file_priv);
462
463 /* ========================================================
464 * Begin inline drm_release
465 */
466
467 DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
468 task_pid_nr(current),
469 (long)old_encode_dev(file_priv->minor->kdev->devt),
470 dev->open_count);
471
472 /* if the master has gone away we can't do anything with the lock */
473 if (file_priv->minor->master)
474 drm_master_release(dev, filp);
475
476 if (drm_core_check_feature(dev, DRIVER_HAVE_DMA))
477 drm_legacy_reclaim_buffers(dev, file_priv);
478
479 drm_events_release(file_priv);
480
481 if (drm_core_check_feature(dev, DRIVER_MODESET)) {
482 drm_fb_release(file_priv);
483 drm_property_destroy_user_blobs(dev, file_priv);
484 }
485
486 if (drm_core_check_feature(dev, DRIVER_GEM))
487 drm_gem_release(dev, file_priv);
488
489 drm_legacy_ctxbitmap_flush(dev, file_priv);
490
491 mutex_lock(&dev->master_mutex);
492
493 if (file_priv->is_master) {
494 struct drm_master *master = file_priv->master;
495
496 /*
497 * Since the master is disappearing, so is the
498 * possibility to lock.
499 */
500 mutex_lock(&dev->struct_mutex);
501 if (master->lock.hw_lock) {
502 if (dev->sigdata.lock == master->lock.hw_lock)
503 dev->sigdata.lock = NULL;
504 master->lock.hw_lock = NULL;
505 master->lock.file_priv = NULL;
506 wake_up_interruptible_all(&master->lock.lock_queue);
507 }
508 mutex_unlock(&dev->struct_mutex);
509
510 if (file_priv->minor->master == file_priv->master) {
511 /* drop the reference held my the minor */
512 if (dev->driver->master_drop)
513 dev->driver->master_drop(dev, file_priv, true);
514 drm_master_put(&file_priv->minor->master);
515 }
516 }
517
518 /* drop the master reference held by the file priv */
519 if (file_priv->master)
520 drm_master_put(&file_priv->master);
521 file_priv->is_master = 0;
522 mutex_unlock(&dev->master_mutex);
523
524 if (dev->driver->postclose)
525 dev->driver->postclose(dev, file_priv);
526
527
528 if (drm_core_check_feature(dev, DRIVER_PRIME))
529 drm_prime_destroy_file_private(&file_priv->prime);
530
531 WARN_ON(!list_empty(&file_priv->event_list));
532
533 put_pid(file_priv->pid);
534 kfree(file_priv);
535
536 /* ========================================================
537 * End inline drm_release
538 */
539
540 if (!--dev->open_count) {
541 retcode = drm_lastclose(dev);
542 if (drm_device_is_unplugged(dev))
543 drm_put_dev(dev);
544 }
545 mutex_unlock(&drm_global_mutex);
546
547 drm_minor_release(minor);
548
549 return retcode;
550}
551EXPORT_SYMBOL(drm_release);
552
553/**
554 * drm_read - read method for DRM file
555 * @filp: file pointer
556 * @buffer: userspace destination pointer for the read
557 * @count: count in bytes to read
558 * @offset: offset to read
559 *
560 * This function must be used by drivers as their .read() #file_operations
561 * method iff they use DRM events for asynchronous signalling to userspace.
562 * Since events are used by the KMS API for vblank and page flip completion this
563 * means all modern display drivers must use it.
564 *
565 * @offset is ignore, DRM events are read like a pipe. Therefore drivers also
566 * must set the .llseek() #file_operation to no_llseek(). Polling support is
567 * provided by drm_poll().
568 *
569 * This function will only ever read a full event. Therefore userspace must
570 * supply a big enough buffer to fit any event to ensure forward progress. Since
571 * the maximum event space is currently 4K it's recommended to just use that for
572 * safety.
573 *
574 * RETURNS:
575 *
576 * Number of bytes read (always aligned to full events, and can be 0) or a
577 * negative error code on failure.
578 */
579ssize_t drm_read(struct file *filp, char __user *buffer,
580 size_t count, loff_t *offset)
581{
582 struct drm_file *file_priv = filp->private_data;
583 struct drm_device *dev = file_priv->minor->dev;
584 ssize_t ret;
585
586 if (!access_ok(VERIFY_WRITE, buffer, count))
587 return -EFAULT;
588
589 ret = mutex_lock_interruptible(&file_priv->event_read_lock);
590 if (ret)
591 return ret;
592
593 for (;;) {
594 struct drm_pending_event *e = NULL;
595
596 spin_lock_irq(&dev->event_lock);
597 if (!list_empty(&file_priv->event_list)) {
598 e = list_first_entry(&file_priv->event_list,
599 struct drm_pending_event, link);
600 file_priv->event_space += e->event->length;
601 list_del(&e->link);
602 }
603 spin_unlock_irq(&dev->event_lock);
604
605 if (e == NULL) {
606 if (ret)
607 break;
608
609 if (filp->f_flags & O_NONBLOCK) {
610 ret = -EAGAIN;
611 break;
612 }
613
614 mutex_unlock(&file_priv->event_read_lock);
615 ret = wait_event_interruptible(file_priv->event_wait,
616 !list_empty(&file_priv->event_list));
617 if (ret >= 0)
618 ret = mutex_lock_interruptible(&file_priv->event_read_lock);
619 if (ret)
620 return ret;
621 } else {
622 unsigned length = e->event->length;
623
624 if (length > count - ret) {
625put_back_event:
626 spin_lock_irq(&dev->event_lock);
627 file_priv->event_space -= length;
628 list_add(&e->link, &file_priv->event_list);
629 spin_unlock_irq(&dev->event_lock);
630 break;
631 }
632
633 if (copy_to_user(buffer + ret, e->event, length)) {
634 if (ret == 0)
635 ret = -EFAULT;
636 goto put_back_event;
637 }
638
639 ret += length;
640 e->destroy(e);
641 }
642 }
643 mutex_unlock(&file_priv->event_read_lock);
644
645 return ret;
646}
647EXPORT_SYMBOL(drm_read);
648
649/**
650 * drm_poll - poll method for DRM file
651 * @filp: file pointer
652 * @wait: poll waiter table
653 *
654 * This function must be used by drivers as their .read() #file_operations
655 * method iff they use DRM events for asynchronous signalling to userspace.
656 * Since events are used by the KMS API for vblank and page flip completion this
657 * means all modern display drivers must use it.
658 *
659 * See also drm_read().
660 *
661 * RETURNS:
662 *
663 * Mask of POLL flags indicating the current status of the file.
664 */
665unsigned int drm_poll(struct file *filp, struct poll_table_struct *wait)
666{
667 struct drm_file *file_priv = filp->private_data;
668 unsigned int mask = 0;
669
670 poll_wait(filp, &file_priv->event_wait, wait);
671
672 if (!list_empty(&file_priv->event_list))
673 mask |= POLLIN | POLLRDNORM;
674
675 return mask;
676}
677EXPORT_SYMBOL(drm_poll);
678
679/**
680 * drm_event_reserve_init_locked - init a DRM event and reserve space for it
681 * @dev: DRM device
682 * @file_priv: DRM file private data
683 * @p: tracking structure for the pending event
684 * @e: actual event data to deliver to userspace
685 *
686 * This function prepares the passed in event for eventual delivery. If the event
687 * doesn't get delivered (because the IOCTL fails later on, before queuing up
688 * anything) then the even must be cancelled and freed using
689 * drm_event_cancel_free(). Successfully initialized events should be sent out
690 * using drm_send_event() or drm_send_event_locked() to signal completion of the
691 * asynchronous event to userspace.
692 *
693 * If callers embedded @p into a larger structure it must be allocated with
694 * kmalloc and @p must be the first member element.
695 *
696 * This is the locked version of drm_event_reserve_init() for callers which
697 * already hold dev->event_lock.
698 *
699 * RETURNS:
700 *
701 * 0 on success or a negative error code on failure.
702 */
703int drm_event_reserve_init_locked(struct drm_device *dev,
704 struct drm_file *file_priv,
705 struct drm_pending_event *p,
706 struct drm_event *e)
707{
708 if (file_priv->event_space < e->length)
709 return -ENOMEM;
710
711 file_priv->event_space -= e->length;
712
713 p->event = e;
714 list_add(&p->pending_link, &file_priv->pending_event_list);
715 p->file_priv = file_priv;
716
717 /* we *could* pass this in as arg, but everyone uses kfree: */
718 p->destroy = (void (*) (struct drm_pending_event *)) kfree;
719
720 return 0;
721}
722EXPORT_SYMBOL(drm_event_reserve_init_locked);
723
724/**
725 * drm_event_reserve_init - init a DRM event and reserve space for it
726 * @dev: DRM device
727 * @file_priv: DRM file private data
728 * @p: tracking structure for the pending event
729 * @e: actual event data to deliver to userspace
730 *
731 * This function prepares the passed in event for eventual delivery. If the event
732 * doesn't get delivered (because the IOCTL fails later on, before queuing up
733 * anything) then the even must be cancelled and freed using
734 * drm_event_cancel_free(). Successfully initialized events should be sent out
735 * using drm_send_event() or drm_send_event_locked() to signal completion of the
736 * asynchronous event to userspace.
737 *
738 * If callers embedded @p into a larger structure it must be allocated with
739 * kmalloc and @p must be the first member element.
740 *
741 * Callers which already hold dev->event_lock should use
742 * drm_event_reserve_init() instead.
743 *
744 * RETURNS:
745 *
746 * 0 on success or a negative error code on failure.
747 */
748int drm_event_reserve_init(struct drm_device *dev,
749 struct drm_file *file_priv,
750 struct drm_pending_event *p,
751 struct drm_event *e)
752{
753 unsigned long flags;
754 int ret;
755
756 spin_lock_irqsave(&dev->event_lock, flags);
757 ret = drm_event_reserve_init_locked(dev, file_priv, p, e);
758 spin_unlock_irqrestore(&dev->event_lock, flags);
759
760 return ret;
761}
762EXPORT_SYMBOL(drm_event_reserve_init);
763
764/**
765 * drm_event_cancel_free - free a DRM event and release it's space
766 * @dev: DRM device
767 * @p: tracking structure for the pending event
768 *
769 * This function frees the event @p initialized with drm_event_reserve_init()
770 * and releases any allocated space.
771 */
772void drm_event_cancel_free(struct drm_device *dev,
773 struct drm_pending_event *p)
774{
775 unsigned long flags;
776 spin_lock_irqsave(&dev->event_lock, flags);
777 if (p->file_priv) {
778 p->file_priv->event_space += p->event->length;
779 list_del(&p->pending_link);
780 }
781 spin_unlock_irqrestore(&dev->event_lock, flags);
782 p->destroy(p);
783}
784EXPORT_SYMBOL(drm_event_cancel_free);
785
786/**
787 * drm_send_event_locked - send DRM event to file descriptor
788 * @dev: DRM device
789 * @e: DRM event to deliver
790 *
791 * This function sends the event @e, initialized with drm_event_reserve_init(),
792 * to its associated userspace DRM file. Callers must already hold
793 * dev->event_lock, see drm_send_event() for the unlocked version.
794 *
795 * Note that the core will take care of unlinking and disarming events when the
796 * corresponding DRM file is closed. Drivers need not worry about whether the
797 * DRM file for this event still exists and can call this function upon
798 * completion of the asynchronous work unconditionally.
799 */
800void drm_send_event_locked(struct drm_device *dev, struct drm_pending_event *e)
801{
802 assert_spin_locked(&dev->event_lock);
803
804 if (!e->file_priv) {
805 e->destroy(e);
806 return;
807 }
808
809 list_del(&e->pending_link);
810 list_add_tail(&e->link,
811 &e->file_priv->event_list);
812 wake_up_interruptible(&e->file_priv->event_wait);
813}
814EXPORT_SYMBOL(drm_send_event_locked);
815
816/**
817 * drm_send_event - send DRM event to file descriptor
818 * @dev: DRM device
819 * @e: DRM event to deliver
820 *
821 * This function sends the event @e, initialized with drm_event_reserve_init(),
822 * to its associated userspace DRM file. This function acquires dev->event_lock,
823 * see drm_send_event_locked() for callers which already hold this lock.
824 *
825 * Note that the core will take care of unlinking and disarming events when the
826 * corresponding DRM file is closed. Drivers need not worry about whether the
827 * DRM file for this event still exists and can call this function upon
828 * completion of the asynchronous work unconditionally.
829 */
830void drm_send_event(struct drm_device *dev, struct drm_pending_event *e)
831{
832 unsigned long irqflags;
833
834 spin_lock_irqsave(&dev->event_lock, irqflags);
835 drm_send_event_locked(dev, e);
836 spin_unlock_irqrestore(&dev->event_lock, irqflags);
837}
838EXPORT_SYMBOL(drm_send_event);