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v5.4
  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 */
 50DEFINE_MUTEX(drm_global_mutex);
 51
 52/**
 53 * DOC: file operations
 54 *
 55 * Drivers must define the file operations structure that forms the DRM
 56 * userspace API entry point, even though most of those operations are
 57 * implemented in the DRM core. The resulting &struct file_operations must be
 58 * stored in the &drm_driver.fops field. The mandatory functions are drm_open(),
 59 * drm_read(), drm_ioctl() and drm_compat_ioctl() if CONFIG_COMPAT is enabled
 60 * Note that drm_compat_ioctl will be NULL if CONFIG_COMPAT=n, so there's no
 61 * need to sprinkle #ifdef into the code. Drivers which implement private ioctls
 62 * that require 32/64 bit compatibility support must provide their own
 63 * &file_operations.compat_ioctl handler that processes private ioctls and calls
 64 * drm_compat_ioctl() for core ioctls.
 65 *
 66 * In addition drm_read() and drm_poll() provide support for DRM events. DRM
 67 * events are a generic and extensible means to send asynchronous events to
 68 * userspace through the file descriptor. They are used to send vblank event and
 69 * page flip completions by the KMS API. But drivers can also use it for their
 70 * own needs, e.g. to signal completion of rendering.
 71 *
 72 * For the driver-side event interface see drm_event_reserve_init() and
 73 * drm_send_event() as the main starting points.
 74 *
 75 * The memory mapping implementation will vary depending on how the driver
 76 * manages memory. Legacy drivers will use the deprecated drm_legacy_mmap()
 77 * function, modern drivers should use one of the provided memory-manager
 78 * specific implementations. For GEM-based drivers this is drm_gem_mmap(), and
 79 * for drivers which use the CMA GEM helpers it's drm_gem_cma_mmap().
 80 *
 81 * No other file operations are supported by the DRM userspace API. Overall the
 82 * following is an example &file_operations structure::
 83 *
 84 *     static const example_drm_fops = {
 85 *             .owner = THIS_MODULE,
 86 *             .open = drm_open,
 87 *             .release = drm_release,
 88 *             .unlocked_ioctl = drm_ioctl,
 89 *             .compat_ioctl = drm_compat_ioctl, // NULL if CONFIG_COMPAT=n
 90 *             .poll = drm_poll,
 91 *             .read = drm_read,
 92 *             .llseek = no_llseek,
 93 *             .mmap = drm_gem_mmap,
 94 *     };
 95 *
 96 * For plain GEM based drivers there is the DEFINE_DRM_GEM_FOPS() macro, and for
 97 * CMA based drivers there is the DEFINE_DRM_GEM_CMA_FOPS() macro to make this
 98 * simpler.
 99 *
100 * The driver's &file_operations must be stored in &drm_driver.fops.
101 *
102 * For driver-private IOCTL handling see the more detailed discussion in
103 * :ref:`IOCTL support in the userland interfaces chapter<drm_driver_ioctl>`.
104 */
105
106/**
107 * drm_file_alloc - allocate file context
108 * @minor: minor to allocate on
109 *
110 * This allocates a new DRM file context. It is not linked into any context and
111 * can be used by the caller freely. Note that the context keeps a pointer to
112 * @minor, so it must be freed before @minor is.
113 *
114 * RETURNS:
115 * Pointer to newly allocated context, ERR_PTR on failure.
116 */
117struct drm_file *drm_file_alloc(struct drm_minor *minor)
118{
119	struct drm_device *dev = minor->dev;
120	struct drm_file *file;
121	int ret;
122
123	file = kzalloc(sizeof(*file), GFP_KERNEL);
124	if (!file)
125		return ERR_PTR(-ENOMEM);
126
127	file->pid = get_pid(task_pid(current));
128	file->minor = minor;
129
130	/* for compatibility root is always authenticated */
131	file->authenticated = capable(CAP_SYS_ADMIN);
132
133	INIT_LIST_HEAD(&file->lhead);
134	INIT_LIST_HEAD(&file->fbs);
135	mutex_init(&file->fbs_lock);
136	INIT_LIST_HEAD(&file->blobs);
137	INIT_LIST_HEAD(&file->pending_event_list);
138	INIT_LIST_HEAD(&file->event_list);
139	init_waitqueue_head(&file->event_wait);
140	file->event_space = 4096; /* set aside 4k for event buffer */
141
142	mutex_init(&file->event_read_lock);
143
144	if (drm_core_check_feature(dev, DRIVER_GEM))
145		drm_gem_open(dev, file);
146
147	if (drm_core_check_feature(dev, DRIVER_SYNCOBJ))
148		drm_syncobj_open(file);
149
150	drm_prime_init_file_private(&file->prime);
151
152	if (dev->driver->open) {
153		ret = dev->driver->open(dev, file);
154		if (ret < 0)
155			goto out_prime_destroy;
156	}
157
158	return file;
159
160out_prime_destroy:
161	drm_prime_destroy_file_private(&file->prime);
162	if (drm_core_check_feature(dev, DRIVER_SYNCOBJ))
163		drm_syncobj_release(file);
164	if (drm_core_check_feature(dev, DRIVER_GEM))
165		drm_gem_release(dev, file);
166	put_pid(file->pid);
167	kfree(file);
168
169	return ERR_PTR(ret);
170}
171
172static void drm_events_release(struct drm_file *file_priv)
173{
174	struct drm_device *dev = file_priv->minor->dev;
175	struct drm_pending_event *e, *et;
176	unsigned long flags;
177
178	spin_lock_irqsave(&dev->event_lock, flags);
179
180	/* Unlink pending events */
181	list_for_each_entry_safe(e, et, &file_priv->pending_event_list,
182				 pending_link) {
183		list_del(&e->pending_link);
184		e->file_priv = NULL;
185	}
186
187	/* Remove unconsumed events */
188	list_for_each_entry_safe(e, et, &file_priv->event_list, link) {
189		list_del(&e->link);
190		kfree(e);
191	}
192
193	spin_unlock_irqrestore(&dev->event_lock, flags);
 
194}
195
196/**
197 * drm_file_free - free file context
198 * @file: context to free, or NULL
199 *
200 * This destroys and deallocates a DRM file context previously allocated via
201 * drm_file_alloc(). The caller must make sure to unlink it from any contexts
202 * before calling this.
203 *
204 * If NULL is passed, this is a no-op.
 
 
205 *
206 * RETURNS:
207 * 0 on success, or error code on failure.
 
208 */
209void drm_file_free(struct drm_file *file)
210{
211	struct drm_device *dev;
 
 
 
212
213	if (!file)
214		return;
215
216	dev = file->minor->dev;
217
218	DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
219		  task_pid_nr(current),
220		  (long)old_encode_dev(file->minor->kdev->devt),
221		  dev->open_count);
222
223	if (drm_core_check_feature(dev, DRIVER_LEGACY) &&
224	    dev->driver->preclose)
225		dev->driver->preclose(dev, file);
226
227	if (drm_core_check_feature(dev, DRIVER_LEGACY))
228		drm_legacy_lock_release(dev, file->filp);
229
230	if (drm_core_check_feature(dev, DRIVER_HAVE_DMA))
231		drm_legacy_reclaim_buffers(dev, file);
 
232
233	drm_events_release(file);
 
234
235	if (drm_core_check_feature(dev, DRIVER_MODESET)) {
236		drm_fb_release(file);
237		drm_property_destroy_user_blobs(dev, file);
 
 
 
 
238	}
 
239
240	if (drm_core_check_feature(dev, DRIVER_SYNCOBJ))
241		drm_syncobj_release(file);
242
243	if (drm_core_check_feature(dev, DRIVER_GEM))
244		drm_gem_release(dev, file);
245
246	drm_legacy_ctxbitmap_flush(dev, file);
247
248	if (drm_is_primary_client(file))
249		drm_master_release(file);
250
251	if (dev->driver->postclose)
252		dev->driver->postclose(dev, file);
253
254	drm_prime_destroy_file_private(&file->prime);
255
256	WARN_ON(!list_empty(&file->event_list));
257
258	put_pid(file->pid);
259	kfree(file);
260}
261
262static void drm_close_helper(struct file *filp)
263{
264	struct drm_file *file_priv = filp->private_data;
265	struct drm_device *dev = file_priv->minor->dev;
266
267	mutex_lock(&dev->filelist_mutex);
268	list_del(&file_priv->lhead);
269	mutex_unlock(&dev->filelist_mutex);
270
271	drm_file_free(file_priv);
272}
 
273
274/*
275 * Check whether DRI will run on this CPU.
276 *
277 * \return non-zero if the DRI will run on this CPU, or zero otherwise.
278 */
279static int drm_cpu_valid(void)
280{
281#if defined(__sparc__) && !defined(__sparc_v9__)
282	return 0;		/* No cmpxchg before v9 sparc. */
283#endif
284	return 1;
285}
286
287/*
288 * Called whenever a process opens /dev/drm.
289 *
290 * \param filp file pointer.
291 * \param minor acquired minor-object.
292 * \return zero on success or a negative number on failure.
293 *
294 * Creates and initializes a drm_file structure for the file private data in \p
295 * filp and add it into the double linked list in \p dev.
296 */
297static int drm_open_helper(struct file *filp, struct drm_minor *minor)
298{
299	struct drm_device *dev = minor->dev;
300	struct drm_file *priv;
301	int ret;
302
303	if (filp->f_flags & O_EXCL)
304		return -EBUSY;	/* No exclusive opens */
305	if (!drm_cpu_valid())
306		return -EINVAL;
307	if (dev->switch_power_state != DRM_SWITCH_POWER_ON && dev->switch_power_state != DRM_SWITCH_POWER_DYNAMIC_OFF)
308		return -EINVAL;
309
310	DRM_DEBUG("pid = %d, minor = %d\n", task_pid_nr(current), minor->index);
311
312	priv = drm_file_alloc(minor);
313	if (IS_ERR(priv))
314		return PTR_ERR(priv);
315
316	if (drm_is_primary_client(priv)) {
317		ret = drm_master_open(priv);
318		if (ret) {
319			drm_file_free(priv);
320			return ret;
321		}
322	}
323
324	filp->private_data = priv;
325	filp->f_mode |= FMODE_UNSIGNED_OFFSET;
326	priv->filp = filp;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
327
328	mutex_lock(&dev->filelist_mutex);
329	list_add(&priv->lhead, &dev->filelist);
330	mutex_unlock(&dev->filelist_mutex);
331
332#ifdef __alpha__
333	/*
334	 * Default the hose
335	 */
336	if (!dev->hose) {
337		struct pci_dev *pci_dev;
338		pci_dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
339		if (pci_dev) {
340			dev->hose = pci_dev->sysdata;
341			pci_dev_put(pci_dev);
342		}
343		if (!dev->hose) {
344			struct pci_bus *b = list_entry(pci_root_buses.next,
345				struct pci_bus, node);
346			if (b)
347				dev->hose = b->sysdata;
348		}
349	}
350#endif
351
352	return 0;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
353}
354
355/**
356 * drm_open - open method for DRM file
357 * @inode: device inode
358 * @filp: file pointer.
359 *
360 * This function must be used by drivers as their &file_operations.open method.
361 * It looks up the correct DRM device and instantiates all the per-file
362 * resources for it. It also calls the &drm_driver.open driver callback.
363 *
364 * RETURNS:
365 *
366 * 0 on success or negative errno value on falure.
367 */
368int drm_open(struct inode *inode, struct file *filp)
369{
370	struct drm_device *dev;
371	struct drm_minor *minor;
372	int retcode;
373	int need_setup = 0;
374
375	minor = drm_minor_acquire(iminor(inode));
376	if (IS_ERR(minor))
377		return PTR_ERR(minor);
378
379	dev = minor->dev;
380	if (!dev->open_count++)
381		need_setup = 1;
382
383	/* share address_space across all char-devs of a single device */
384	filp->f_mapping = dev->anon_inode->i_mapping;
 
 
 
 
385
386	retcode = drm_open_helper(filp, minor);
387	if (retcode)
388		goto err_undo;
389	if (need_setup) {
390		retcode = drm_legacy_setup(dev);
391		if (retcode) {
392			drm_close_helper(filp);
393			goto err_undo;
394		}
395	}
396	return 0;
397
398err_undo:
399	dev->open_count--;
400	drm_minor_release(minor);
401	return retcode;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
402}
403EXPORT_SYMBOL(drm_open);
404
405void drm_lastclose(struct drm_device * dev)
406{
407	DRM_DEBUG("\n");
408
409	if (dev->driver->lastclose)
410		dev->driver->lastclose(dev);
411	DRM_DEBUG("driver lastclose completed\n");
412
413	if (drm_core_check_feature(dev, DRIVER_LEGACY))
414		drm_legacy_dev_reinit(dev);
415
416	drm_client_dev_restore(dev);
417}
418
419/**
420 * drm_release - release method for DRM file
421 * @inode: device inode
422 * @filp: file pointer.
423 *
424 * This function must be used by drivers as their &file_operations.release
425 * method. It frees any resources associated with the open file, and calls the
426 * &drm_driver.postclose driver callback. If this is the last open file for the
427 * DRM device also proceeds to call the &drm_driver.lastclose driver callback.
428 *
429 * RETURNS:
430 *
431 * Always succeeds and returns 0.
432 */
433int drm_release(struct inode *inode, struct file *filp)
434{
435	struct drm_file *file_priv = filp->private_data;
436	struct drm_minor *minor = file_priv->minor;
437	struct drm_device *dev = minor->dev;
438
439	mutex_lock(&drm_global_mutex);
440
441	DRM_DEBUG("open_count = %d\n", dev->open_count);
442
443	drm_close_helper(filp);
 
 
444
445	if (!--dev->open_count)
446		drm_lastclose(dev);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
447
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
448	mutex_unlock(&drm_global_mutex);
449
450	drm_minor_release(minor);
451
452	return 0;
453}
454EXPORT_SYMBOL(drm_release);
455
456/**
457 * drm_read - read method for DRM file
458 * @filp: file pointer
459 * @buffer: userspace destination pointer for the read
460 * @count: count in bytes to read
461 * @offset: offset to read
462 *
463 * This function must be used by drivers as their &file_operations.read
464 * method iff they use DRM events for asynchronous signalling to userspace.
465 * Since events are used by the KMS API for vblank and page flip completion this
466 * means all modern display drivers must use it.
467 *
468 * @offset is ignored, DRM events are read like a pipe. Therefore drivers also
469 * must set the &file_operation.llseek to no_llseek(). Polling support is
470 * provided by drm_poll().
471 *
472 * This function will only ever read a full event. Therefore userspace must
473 * supply a big enough buffer to fit any event to ensure forward progress. Since
474 * the maximum event space is currently 4K it's recommended to just use that for
475 * safety.
476 *
477 * RETURNS:
478 *
479 * Number of bytes read (always aligned to full events, and can be 0) or a
480 * negative error code on failure.
481 */
482ssize_t drm_read(struct file *filp, char __user *buffer,
483		 size_t count, loff_t *offset)
484{
485	struct drm_file *file_priv = filp->private_data;
486	struct drm_device *dev = file_priv->minor->dev;
487	ssize_t ret;
488
489	if (!access_ok(buffer, count))
490		return -EFAULT;
491
492	ret = mutex_lock_interruptible(&file_priv->event_read_lock);
493	if (ret)
494		return ret;
495
496	for (;;) {
497		struct drm_pending_event *e = NULL;
498
499		spin_lock_irq(&dev->event_lock);
500		if (!list_empty(&file_priv->event_list)) {
501			e = list_first_entry(&file_priv->event_list,
502					struct drm_pending_event, link);
503			file_priv->event_space += e->event->length;
504			list_del(&e->link);
505		}
506		spin_unlock_irq(&dev->event_lock);
507
508		if (e == NULL) {
509			if (ret)
510				break;
511
512			if (filp->f_flags & O_NONBLOCK) {
513				ret = -EAGAIN;
514				break;
515			}
516
517			mutex_unlock(&file_priv->event_read_lock);
518			ret = wait_event_interruptible(file_priv->event_wait,
519						       !list_empty(&file_priv->event_list));
520			if (ret >= 0)
521				ret = mutex_lock_interruptible(&file_priv->event_read_lock);
522			if (ret)
523				return ret;
524		} else {
525			unsigned length = e->event->length;
526
527			if (length > count - ret) {
528put_back_event:
529				spin_lock_irq(&dev->event_lock);
530				file_priv->event_space -= length;
531				list_add(&e->link, &file_priv->event_list);
532				spin_unlock_irq(&dev->event_lock);
533				wake_up_interruptible(&file_priv->event_wait);
534				break;
535			}
536
537			if (copy_to_user(buffer + ret, e->event, length)) {
538				if (ret == 0)
539					ret = -EFAULT;
540				goto put_back_event;
541			}
542
543			ret += length;
544			kfree(e);
545		}
546	}
547	mutex_unlock(&file_priv->event_read_lock);
548
549	return ret;
550}
551EXPORT_SYMBOL(drm_read);
552
553/**
554 * drm_poll - poll method for DRM file
555 * @filp: file pointer
556 * @wait: poll waiter table
557 *
558 * This function must be used by drivers as their &file_operations.read method
559 * iff they use DRM events for asynchronous signalling to userspace.  Since
560 * events are used by the KMS API for vblank and page flip completion this means
561 * all modern display drivers must use it.
562 *
563 * See also drm_read().
564 *
565 * RETURNS:
566 *
567 * Mask of POLL flags indicating the current status of the file.
568 */
569__poll_t drm_poll(struct file *filp, struct poll_table_struct *wait)
570{
571	struct drm_file *file_priv = filp->private_data;
572	__poll_t mask = 0;
573
574	poll_wait(filp, &file_priv->event_wait, wait);
575
576	if (!list_empty(&file_priv->event_list))
577		mask |= EPOLLIN | EPOLLRDNORM;
578
579	return mask;
580}
581EXPORT_SYMBOL(drm_poll);
582
583/**
584 * drm_event_reserve_init_locked - init a DRM event and reserve space for it
585 * @dev: DRM device
586 * @file_priv: DRM file private data
587 * @p: tracking structure for the pending event
588 * @e: actual event data to deliver to userspace
589 *
590 * This function prepares the passed in event for eventual delivery. If the event
591 * doesn't get delivered (because the IOCTL fails later on, before queuing up
592 * anything) then the even must be cancelled and freed using
593 * drm_event_cancel_free(). Successfully initialized events should be sent out
594 * using drm_send_event() or drm_send_event_locked() to signal completion of the
595 * asynchronous event to userspace.
596 *
597 * If callers embedded @p into a larger structure it must be allocated with
598 * kmalloc and @p must be the first member element.
599 *
600 * This is the locked version of drm_event_reserve_init() for callers which
601 * already hold &drm_device.event_lock.
602 *
603 * RETURNS:
604 *
605 * 0 on success or a negative error code on failure.
606 */
607int drm_event_reserve_init_locked(struct drm_device *dev,
608				  struct drm_file *file_priv,
609				  struct drm_pending_event *p,
610				  struct drm_event *e)
611{
612	if (file_priv->event_space < e->length)
613		return -ENOMEM;
614
615	file_priv->event_space -= e->length;
616
617	p->event = e;
618	list_add(&p->pending_link, &file_priv->pending_event_list);
619	p->file_priv = file_priv;
620
621	return 0;
622}
623EXPORT_SYMBOL(drm_event_reserve_init_locked);
624
625/**
626 * drm_event_reserve_init - init a DRM event and reserve space for it
627 * @dev: DRM device
628 * @file_priv: DRM file private data
629 * @p: tracking structure for the pending event
630 * @e: actual event data to deliver to userspace
631 *
632 * This function prepares the passed in event for eventual delivery. If the event
633 * doesn't get delivered (because the IOCTL fails later on, before queuing up
634 * anything) then the even must be cancelled and freed using
635 * drm_event_cancel_free(). Successfully initialized events should be sent out
636 * using drm_send_event() or drm_send_event_locked() to signal completion of the
637 * asynchronous event to userspace.
638 *
639 * If callers embedded @p into a larger structure it must be allocated with
640 * kmalloc and @p must be the first member element.
641 *
642 * Callers which already hold &drm_device.event_lock should use
643 * drm_event_reserve_init_locked() instead.
644 *
645 * RETURNS:
646 *
647 * 0 on success or a negative error code on failure.
648 */
649int drm_event_reserve_init(struct drm_device *dev,
650			   struct drm_file *file_priv,
651			   struct drm_pending_event *p,
652			   struct drm_event *e)
653{
654	unsigned long flags;
655	int ret;
656
657	spin_lock_irqsave(&dev->event_lock, flags);
658	ret = drm_event_reserve_init_locked(dev, file_priv, p, e);
659	spin_unlock_irqrestore(&dev->event_lock, flags);
660
661	return ret;
662}
663EXPORT_SYMBOL(drm_event_reserve_init);
664
665/**
666 * drm_event_cancel_free - free a DRM event and release its space
667 * @dev: DRM device
668 * @p: tracking structure for the pending event
669 *
670 * This function frees the event @p initialized with drm_event_reserve_init()
671 * and releases any allocated space. It is used to cancel an event when the
672 * nonblocking operation could not be submitted and needed to be aborted.
673 */
674void drm_event_cancel_free(struct drm_device *dev,
675			   struct drm_pending_event *p)
676{
677	unsigned long flags;
678	spin_lock_irqsave(&dev->event_lock, flags);
679	if (p->file_priv) {
680		p->file_priv->event_space += p->event->length;
681		list_del(&p->pending_link);
682	}
683	spin_unlock_irqrestore(&dev->event_lock, flags);
684
685	if (p->fence)
686		dma_fence_put(p->fence);
687
688	kfree(p);
689}
690EXPORT_SYMBOL(drm_event_cancel_free);
691
692/**
693 * drm_send_event_locked - send DRM event to file descriptor
694 * @dev: DRM device
695 * @e: DRM event to deliver
696 *
697 * This function sends the event @e, initialized with drm_event_reserve_init(),
698 * to its associated userspace DRM file. Callers must already hold
699 * &drm_device.event_lock, see drm_send_event() for the unlocked version.
700 *
701 * Note that the core will take care of unlinking and disarming events when the
702 * corresponding DRM file is closed. Drivers need not worry about whether the
703 * DRM file for this event still exists and can call this function upon
704 * completion of the asynchronous work unconditionally.
705 */
706void drm_send_event_locked(struct drm_device *dev, struct drm_pending_event *e)
707{
708	assert_spin_locked(&dev->event_lock);
709
710	if (e->completion) {
711		complete_all(e->completion);
712		e->completion_release(e->completion);
713		e->completion = NULL;
714	}
715
716	if (e->fence) {
717		dma_fence_signal(e->fence);
718		dma_fence_put(e->fence);
719	}
720
721	if (!e->file_priv) {
722		kfree(e);
723		return;
724	}
725
726	list_del(&e->pending_link);
727	list_add_tail(&e->link,
728		      &e->file_priv->event_list);
729	wake_up_interruptible(&e->file_priv->event_wait);
730}
731EXPORT_SYMBOL(drm_send_event_locked);
732
733/**
734 * drm_send_event - send DRM event to file descriptor
735 * @dev: DRM device
736 * @e: DRM event to deliver
737 *
738 * This function sends the event @e, initialized with drm_event_reserve_init(),
739 * to its associated userspace DRM file. This function acquires
740 * &drm_device.event_lock, see drm_send_event_locked() for callers which already
741 * hold this lock.
742 *
743 * Note that the core will take care of unlinking and disarming events when the
744 * corresponding DRM file is closed. Drivers need not worry about whether the
745 * DRM file for this event still exists and can call this function upon
746 * completion of the asynchronous work unconditionally.
747 */
748void drm_send_event(struct drm_device *dev, struct drm_pending_event *e)
749{
750	unsigned long irqflags;
751
752	spin_lock_irqsave(&dev->event_lock, irqflags);
753	drm_send_event_locked(dev, e);
754	spin_unlock_irqrestore(&dev->event_lock, irqflags);
755}
756EXPORT_SYMBOL(drm_send_event);
v4.17
  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);