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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/anon_inodes.h>
 35#include <linux/dma-fence.h>
 36#include <linux/file.h>
 37#include <linux/module.h>
 38#include <linux/pci.h>
 39#include <linux/poll.h>
 40#include <linux/slab.h>
 41
 42#include <drm/drm_client.h>
 43#include <drm/drm_drv.h>
 44#include <drm/drm_file.h>
 45#include <drm/drm_print.h>
 46
 47#include "drm_crtc_internal.h"
 48#include "drm_internal.h"
 49#include "drm_legacy.h"
 50
 51/* from BKL pushdown */
 52DEFINE_MUTEX(drm_global_mutex);
 53
 54bool drm_dev_needs_global_mutex(struct drm_device *dev)
 55{
 56	/*
 57	 * Legacy drivers rely on all kinds of BKL locking semantics, don't
 58	 * bother. They also still need BKL locking for their ioctls, so better
 59	 * safe than sorry.
 60	 */
 61	if (drm_core_check_feature(dev, DRIVER_LEGACY))
 62		return true;
 63
 64	/*
 65	 * The deprecated ->load callback must be called after the driver is
 66	 * already registered. This means such drivers rely on the BKL to make
 67	 * sure an open can't proceed until the driver is actually fully set up.
 68	 * Similar hilarity holds for the unload callback.
 69	 */
 70	if (dev->driver->load || dev->driver->unload)
 71		return true;
 72
 73	/*
 74	 * Drivers with the lastclose callback assume that it's synchronized
 75	 * against concurrent opens, which again needs the BKL. The proper fix
 76	 * is to use the drm_client infrastructure with proper locking for each
 77	 * client.
 78	 */
 79	if (dev->driver->lastclose)
 80		return true;
 81
 82	return false;
 83}
 84
 85/**
 86 * DOC: file operations
 87 *
 88 * Drivers must define the file operations structure that forms the DRM
 89 * userspace API entry point, even though most of those operations are
 90 * implemented in the DRM core. The resulting &struct file_operations must be
 91 * stored in the &drm_driver.fops field. The mandatory functions are drm_open(),
 92 * drm_read(), drm_ioctl() and drm_compat_ioctl() if CONFIG_COMPAT is enabled
 93 * Note that drm_compat_ioctl will be NULL if CONFIG_COMPAT=n, so there's no
 94 * need to sprinkle #ifdef into the code. Drivers which implement private ioctls
 95 * that require 32/64 bit compatibility support must provide their own
 96 * &file_operations.compat_ioctl handler that processes private ioctls and calls
 97 * drm_compat_ioctl() for core ioctls.
 98 *
 99 * In addition drm_read() and drm_poll() provide support for DRM events. DRM
100 * events are a generic and extensible means to send asynchronous events to
101 * userspace through the file descriptor. They are used to send vblank event and
102 * page flip completions by the KMS API. But drivers can also use it for their
103 * own needs, e.g. to signal completion of rendering.
104 *
105 * For the driver-side event interface see drm_event_reserve_init() and
106 * drm_send_event() as the main starting points.
107 *
108 * The memory mapping implementation will vary depending on how the driver
109 * manages memory. Legacy drivers will use the deprecated drm_legacy_mmap()
110 * function, modern drivers should use one of the provided memory-manager
111 * specific implementations. For GEM-based drivers this is drm_gem_mmap().
112 *
113 * No other file operations are supported by the DRM userspace API. Overall the
114 * following is an example &file_operations structure::
115 *
116 *     static const example_drm_fops = {
117 *             .owner = THIS_MODULE,
118 *             .open = drm_open,
119 *             .release = drm_release,
120 *             .unlocked_ioctl = drm_ioctl,
121 *             .compat_ioctl = drm_compat_ioctl, // NULL if CONFIG_COMPAT=n
122 *             .poll = drm_poll,
123 *             .read = drm_read,
124 *             .llseek = no_llseek,
125 *             .mmap = drm_gem_mmap,
126 *     };
127 *
128 * For plain GEM based drivers there is the DEFINE_DRM_GEM_FOPS() macro, and for
129 * DMA based drivers there is the DEFINE_DRM_GEM_DMA_FOPS() macro to make this
130 * simpler.
131 *
132 * The driver's &file_operations must be stored in &drm_driver.fops.
133 *
134 * For driver-private IOCTL handling see the more detailed discussion in
135 * :ref:`IOCTL support in the userland interfaces chapter<drm_driver_ioctl>`.
136 */
137
138/**
139 * drm_file_alloc - allocate file context
140 * @minor: minor to allocate on
141 *
142 * This allocates a new DRM file context. It is not linked into any context and
143 * can be used by the caller freely. Note that the context keeps a pointer to
144 * @minor, so it must be freed before @minor is.
145 *
146 * RETURNS:
147 * Pointer to newly allocated context, ERR_PTR on failure.
148 */
149struct drm_file *drm_file_alloc(struct drm_minor *minor)
150{
151	struct drm_device *dev = minor->dev;
152	struct drm_file *file;
153	int ret;
154
155	file = kzalloc(sizeof(*file), GFP_KERNEL);
156	if (!file)
157		return ERR_PTR(-ENOMEM);
158
159	file->pid = get_pid(task_pid(current));
160	file->minor = minor;
161
162	/* for compatibility root is always authenticated */
163	file->authenticated = capable(CAP_SYS_ADMIN);
164
165	INIT_LIST_HEAD(&file->lhead);
166	INIT_LIST_HEAD(&file->fbs);
167	mutex_init(&file->fbs_lock);
168	INIT_LIST_HEAD(&file->blobs);
169	INIT_LIST_HEAD(&file->pending_event_list);
170	INIT_LIST_HEAD(&file->event_list);
171	init_waitqueue_head(&file->event_wait);
172	file->event_space = 4096; /* set aside 4k for event buffer */
173
174	spin_lock_init(&file->master_lookup_lock);
175	mutex_init(&file->event_read_lock);
176
177	if (drm_core_check_feature(dev, DRIVER_GEM))
178		drm_gem_open(dev, file);
179
180	if (drm_core_check_feature(dev, DRIVER_SYNCOBJ))
181		drm_syncobj_open(file);
182
183	drm_prime_init_file_private(&file->prime);
184
185	if (dev->driver->open) {
186		ret = dev->driver->open(dev, file);
187		if (ret < 0)
188			goto out_prime_destroy;
189	}
190
191	return file;
192
193out_prime_destroy:
194	drm_prime_destroy_file_private(&file->prime);
195	if (drm_core_check_feature(dev, DRIVER_SYNCOBJ))
196		drm_syncobj_release(file);
197	if (drm_core_check_feature(dev, DRIVER_GEM))
198		drm_gem_release(dev, file);
199	put_pid(file->pid);
200	kfree(file);
201
202	return ERR_PTR(ret);
203}
204
205static void drm_events_release(struct drm_file *file_priv)
206{
207	struct drm_device *dev = file_priv->minor->dev;
208	struct drm_pending_event *e, *et;
209	unsigned long flags;
210
211	spin_lock_irqsave(&dev->event_lock, flags);
212
213	/* Unlink pending events */
214	list_for_each_entry_safe(e, et, &file_priv->pending_event_list,
215				 pending_link) {
216		list_del(&e->pending_link);
217		e->file_priv = NULL;
218	}
219
220	/* Remove unconsumed events */
221	list_for_each_entry_safe(e, et, &file_priv->event_list, link) {
222		list_del(&e->link);
223		kfree(e);
224	}
225
226	spin_unlock_irqrestore(&dev->event_lock, flags);
227}
228
229/**
230 * drm_file_free - free file context
231 * @file: context to free, or NULL
232 *
233 * This destroys and deallocates a DRM file context previously allocated via
234 * drm_file_alloc(). The caller must make sure to unlink it from any contexts
235 * before calling this.
236 *
237 * If NULL is passed, this is a no-op.
238 */
239void drm_file_free(struct drm_file *file)
240{
241	struct drm_device *dev;
242
243	if (!file)
244		return;
245
246	dev = file->minor->dev;
247
248	DRM_DEBUG("comm=\"%s\", pid=%d, dev=0x%lx, open_count=%d\n",
249		  current->comm, task_pid_nr(current),
250		  (long)old_encode_dev(file->minor->kdev->devt),
251		  atomic_read(&dev->open_count));
252
253#ifdef CONFIG_DRM_LEGACY
254	if (drm_core_check_feature(dev, DRIVER_LEGACY) &&
255	    dev->driver->preclose)
256		dev->driver->preclose(dev, file);
257#endif
258
259	if (drm_core_check_feature(dev, DRIVER_LEGACY))
260		drm_legacy_lock_release(dev, file->filp);
261
262	if (drm_core_check_feature(dev, DRIVER_HAVE_DMA))
263		drm_legacy_reclaim_buffers(dev, file);
264
265	drm_events_release(file);
266
267	if (drm_core_check_feature(dev, DRIVER_MODESET)) {
268		drm_fb_release(file);
269		drm_property_destroy_user_blobs(dev, file);
270	}
271
272	if (drm_core_check_feature(dev, DRIVER_SYNCOBJ))
273		drm_syncobj_release(file);
274
275	if (drm_core_check_feature(dev, DRIVER_GEM))
276		drm_gem_release(dev, file);
277
278	drm_legacy_ctxbitmap_flush(dev, file);
279
280	if (drm_is_primary_client(file))
281		drm_master_release(file);
282
283	if (dev->driver->postclose)
284		dev->driver->postclose(dev, file);
285
286	drm_prime_destroy_file_private(&file->prime);
287
288	WARN_ON(!list_empty(&file->event_list));
289
290	put_pid(file->pid);
291	kfree(file);
292}
293
294static void drm_close_helper(struct file *filp)
295{
296	struct drm_file *file_priv = filp->private_data;
297	struct drm_device *dev = file_priv->minor->dev;
298
299	mutex_lock(&dev->filelist_mutex);
300	list_del(&file_priv->lhead);
301	mutex_unlock(&dev->filelist_mutex);
302
303	drm_file_free(file_priv);
304}
305
306/*
307 * Check whether DRI will run on this CPU.
308 *
309 * \return non-zero if the DRI will run on this CPU, or zero otherwise.
310 */
311static int drm_cpu_valid(void)
312{
313#if defined(__sparc__) && !defined(__sparc_v9__)
314	return 0;		/* No cmpxchg before v9 sparc. */
315#endif
316	return 1;
317}
318
319/*
320 * Called whenever a process opens a drm node
321 *
322 * \param filp file pointer.
323 * \param minor acquired minor-object.
324 * \return zero on success or a negative number on failure.
325 *
326 * Creates and initializes a drm_file structure for the file private data in \p
327 * filp and add it into the double linked list in \p dev.
328 */
329int drm_open_helper(struct file *filp, struct drm_minor *minor)
330{
331	struct drm_device *dev = minor->dev;
332	struct drm_file *priv;
333	int ret;
334
335	if (filp->f_flags & O_EXCL)
336		return -EBUSY;	/* No exclusive opens */
337	if (!drm_cpu_valid())
338		return -EINVAL;
339	if (dev->switch_power_state != DRM_SWITCH_POWER_ON &&
340	    dev->switch_power_state != DRM_SWITCH_POWER_DYNAMIC_OFF)
341		return -EINVAL;
342
343	DRM_DEBUG("comm=\"%s\", pid=%d, minor=%d\n", current->comm,
344		  task_pid_nr(current), minor->index);
345
346	priv = drm_file_alloc(minor);
347	if (IS_ERR(priv))
348		return PTR_ERR(priv);
349
350	if (drm_is_primary_client(priv)) {
351		ret = drm_master_open(priv);
352		if (ret) {
353			drm_file_free(priv);
354			return ret;
355		}
356	}
357
358	filp->private_data = priv;
359	filp->f_mode |= FMODE_UNSIGNED_OFFSET;
360	priv->filp = filp;
361
362	mutex_lock(&dev->filelist_mutex);
363	list_add(&priv->lhead, &dev->filelist);
364	mutex_unlock(&dev->filelist_mutex);
365
366#ifdef CONFIG_DRM_LEGACY
367#ifdef __alpha__
368	/*
369	 * Default the hose
370	 */
371	if (!dev->hose) {
372		struct pci_dev *pci_dev;
373
374		pci_dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
375		if (pci_dev) {
376			dev->hose = pci_dev->sysdata;
377			pci_dev_put(pci_dev);
378		}
379		if (!dev->hose) {
380			struct pci_bus *b = list_entry(pci_root_buses.next,
381				struct pci_bus, node);
382			if (b)
383				dev->hose = b->sysdata;
384		}
385	}
386#endif
387#endif
388
389	return 0;
390}
391
392/**
393 * drm_open - open method for DRM file
394 * @inode: device inode
395 * @filp: file pointer.
396 *
397 * This function must be used by drivers as their &file_operations.open method.
398 * It looks up the correct DRM device and instantiates all the per-file
399 * resources for it. It also calls the &drm_driver.open driver callback.
400 *
401 * RETURNS:
402 *
403 * 0 on success or negative errno value on failure.
404 */
405int drm_open(struct inode *inode, struct file *filp)
406{
407	struct drm_device *dev;
408	struct drm_minor *minor;
409	int retcode;
410	int need_setup = 0;
411
412	minor = drm_minor_acquire(iminor(inode));
413	if (IS_ERR(minor))
414		return PTR_ERR(minor);
415
416	dev = minor->dev;
417	if (drm_dev_needs_global_mutex(dev))
418		mutex_lock(&drm_global_mutex);
419
420	if (!atomic_fetch_inc(&dev->open_count))
421		need_setup = 1;
422
423	/* share address_space across all char-devs of a single device */
424	filp->f_mapping = dev->anon_inode->i_mapping;
425
426	retcode = drm_open_helper(filp, minor);
427	if (retcode)
428		goto err_undo;
429	if (need_setup) {
430		retcode = drm_legacy_setup(dev);
431		if (retcode) {
432			drm_close_helper(filp);
433			goto err_undo;
434		}
435	}
436
437	if (drm_dev_needs_global_mutex(dev))
438		mutex_unlock(&drm_global_mutex);
439
440	return 0;
441
442err_undo:
443	atomic_dec(&dev->open_count);
444	if (drm_dev_needs_global_mutex(dev))
445		mutex_unlock(&drm_global_mutex);
446	drm_minor_release(minor);
447	return retcode;
448}
449EXPORT_SYMBOL(drm_open);
450
451void drm_lastclose(struct drm_device * dev)
452{
453	DRM_DEBUG("\n");
454
455	if (dev->driver->lastclose)
456		dev->driver->lastclose(dev);
457	DRM_DEBUG("driver lastclose completed\n");
458
459	if (drm_core_check_feature(dev, DRIVER_LEGACY))
460		drm_legacy_dev_reinit(dev);
461
462	drm_client_dev_restore(dev);
463}
464
465/**
466 * drm_release - release method for DRM file
467 * @inode: device inode
468 * @filp: file pointer.
469 *
470 * This function must be used by drivers as their &file_operations.release
471 * method. It frees any resources associated with the open file, and calls the
472 * &drm_driver.postclose driver callback. If this is the last open file for the
473 * DRM device also proceeds to call the &drm_driver.lastclose driver callback.
474 *
475 * RETURNS:
476 *
477 * Always succeeds and returns 0.
478 */
479int drm_release(struct inode *inode, struct file *filp)
480{
481	struct drm_file *file_priv = filp->private_data;
482	struct drm_minor *minor = file_priv->minor;
483	struct drm_device *dev = minor->dev;
484
485	if (drm_dev_needs_global_mutex(dev))
486		mutex_lock(&drm_global_mutex);
487
488	DRM_DEBUG("open_count = %d\n", atomic_read(&dev->open_count));
489
490	drm_close_helper(filp);
491
492	if (atomic_dec_and_test(&dev->open_count))
493		drm_lastclose(dev);
494
495	if (drm_dev_needs_global_mutex(dev))
496		mutex_unlock(&drm_global_mutex);
497
498	drm_minor_release(minor);
499
500	return 0;
501}
502EXPORT_SYMBOL(drm_release);
503
504/**
505 * drm_release_noglobal - release method for DRM file
506 * @inode: device inode
507 * @filp: file pointer.
508 *
509 * This function may be used by drivers as their &file_operations.release
510 * method. It frees any resources associated with the open file prior to taking
511 * the drm_global_mutex, which then calls the &drm_driver.postclose driver
512 * callback. If this is the last open file for the DRM device also proceeds to
513 * call the &drm_driver.lastclose driver callback.
514 *
515 * RETURNS:
516 *
517 * Always succeeds and returns 0.
518 */
519int drm_release_noglobal(struct inode *inode, struct file *filp)
520{
521	struct drm_file *file_priv = filp->private_data;
522	struct drm_minor *minor = file_priv->minor;
523	struct drm_device *dev = minor->dev;
524
525	drm_close_helper(filp);
526
527	if (atomic_dec_and_mutex_lock(&dev->open_count, &drm_global_mutex)) {
528		drm_lastclose(dev);
529		mutex_unlock(&drm_global_mutex);
530	}
531
532	drm_minor_release(minor);
533
534	return 0;
535}
536EXPORT_SYMBOL(drm_release_noglobal);
537
538/**
539 * drm_read - read method for DRM file
540 * @filp: file pointer
541 * @buffer: userspace destination pointer for the read
542 * @count: count in bytes to read
543 * @offset: offset to read
544 *
545 * This function must be used by drivers as their &file_operations.read
546 * method if they use DRM events for asynchronous signalling to userspace.
547 * Since events are used by the KMS API for vblank and page flip completion this
548 * means all modern display drivers must use it.
549 *
550 * @offset is ignored, DRM events are read like a pipe. Polling support is
551 * provided by drm_poll().
552 *
553 * This function will only ever read a full event. Therefore userspace must
554 * supply a big enough buffer to fit any event to ensure forward progress. Since
555 * the maximum event space is currently 4K it's recommended to just use that for
556 * safety.
557 *
558 * RETURNS:
559 *
560 * Number of bytes read (always aligned to full events, and can be 0) or a
561 * negative error code on failure.
562 */
563ssize_t drm_read(struct file *filp, char __user *buffer,
564		 size_t count, loff_t *offset)
565{
566	struct drm_file *file_priv = filp->private_data;
567	struct drm_device *dev = file_priv->minor->dev;
568	ssize_t ret;
569
570	ret = mutex_lock_interruptible(&file_priv->event_read_lock);
571	if (ret)
572		return ret;
573
574	for (;;) {
575		struct drm_pending_event *e = NULL;
576
577		spin_lock_irq(&dev->event_lock);
578		if (!list_empty(&file_priv->event_list)) {
579			e = list_first_entry(&file_priv->event_list,
580					struct drm_pending_event, link);
581			file_priv->event_space += e->event->length;
582			list_del(&e->link);
583		}
584		spin_unlock_irq(&dev->event_lock);
585
586		if (e == NULL) {
587			if (ret)
588				break;
589
590			if (filp->f_flags & O_NONBLOCK) {
591				ret = -EAGAIN;
592				break;
593			}
594
595			mutex_unlock(&file_priv->event_read_lock);
596			ret = wait_event_interruptible(file_priv->event_wait,
597						       !list_empty(&file_priv->event_list));
598			if (ret >= 0)
599				ret = mutex_lock_interruptible(&file_priv->event_read_lock);
600			if (ret)
601				return ret;
602		} else {
603			unsigned length = e->event->length;
604
605			if (length > count - ret) {
606put_back_event:
607				spin_lock_irq(&dev->event_lock);
608				file_priv->event_space -= length;
609				list_add(&e->link, &file_priv->event_list);
610				spin_unlock_irq(&dev->event_lock);
611				wake_up_interruptible_poll(&file_priv->event_wait,
612					EPOLLIN | EPOLLRDNORM);
613				break;
614			}
615
616			if (copy_to_user(buffer + ret, e->event, length)) {
617				if (ret == 0)
618					ret = -EFAULT;
619				goto put_back_event;
620			}
621
622			ret += length;
623			kfree(e);
624		}
625	}
626	mutex_unlock(&file_priv->event_read_lock);
627
628	return ret;
629}
630EXPORT_SYMBOL(drm_read);
631
632/**
633 * drm_poll - poll method for DRM file
634 * @filp: file pointer
635 * @wait: poll waiter table
636 *
637 * This function must be used by drivers as their &file_operations.read method
638 * if they use DRM events for asynchronous signalling to userspace.  Since
639 * events are used by the KMS API for vblank and page flip completion this means
640 * all modern display drivers must use it.
641 *
642 * See also drm_read().
643 *
644 * RETURNS:
645 *
646 * Mask of POLL flags indicating the current status of the file.
647 */
648__poll_t drm_poll(struct file *filp, struct poll_table_struct *wait)
649{
650	struct drm_file *file_priv = filp->private_data;
651	__poll_t mask = 0;
652
653	poll_wait(filp, &file_priv->event_wait, wait);
654
655	if (!list_empty(&file_priv->event_list))
656		mask |= EPOLLIN | EPOLLRDNORM;
657
658	return mask;
659}
660EXPORT_SYMBOL(drm_poll);
661
662/**
663 * drm_event_reserve_init_locked - init a DRM event and reserve space for it
664 * @dev: DRM device
665 * @file_priv: DRM file private data
666 * @p: tracking structure for the pending event
667 * @e: actual event data to deliver to userspace
668 *
669 * This function prepares the passed in event for eventual delivery. If the event
670 * doesn't get delivered (because the IOCTL fails later on, before queuing up
671 * anything) then the even must be cancelled and freed using
672 * drm_event_cancel_free(). Successfully initialized events should be sent out
673 * using drm_send_event() or drm_send_event_locked() to signal completion of the
674 * asynchronous event to userspace.
675 *
676 * If callers embedded @p into a larger structure it must be allocated with
677 * kmalloc and @p must be the first member element.
678 *
679 * This is the locked version of drm_event_reserve_init() for callers which
680 * already hold &drm_device.event_lock.
681 *
682 * RETURNS:
683 *
684 * 0 on success or a negative error code on failure.
685 */
686int drm_event_reserve_init_locked(struct drm_device *dev,
687				  struct drm_file *file_priv,
688				  struct drm_pending_event *p,
689				  struct drm_event *e)
690{
691	if (file_priv->event_space < e->length)
692		return -ENOMEM;
693
694	file_priv->event_space -= e->length;
695
696	p->event = e;
697	list_add(&p->pending_link, &file_priv->pending_event_list);
698	p->file_priv = file_priv;
699
700	return 0;
701}
702EXPORT_SYMBOL(drm_event_reserve_init_locked);
703
704/**
705 * drm_event_reserve_init - init a DRM event and reserve space for it
706 * @dev: DRM device
707 * @file_priv: DRM file private data
708 * @p: tracking structure for the pending event
709 * @e: actual event data to deliver to userspace
710 *
711 * This function prepares the passed in event for eventual delivery. If the event
712 * doesn't get delivered (because the IOCTL fails later on, before queuing up
713 * anything) then the even must be cancelled and freed using
714 * drm_event_cancel_free(). Successfully initialized events should be sent out
715 * using drm_send_event() or drm_send_event_locked() to signal completion of the
716 * asynchronous event to userspace.
717 *
718 * If callers embedded @p into a larger structure it must be allocated with
719 * kmalloc and @p must be the first member element.
720 *
721 * Callers which already hold &drm_device.event_lock should use
722 * drm_event_reserve_init_locked() instead.
723 *
724 * RETURNS:
725 *
726 * 0 on success or a negative error code on failure.
727 */
728int drm_event_reserve_init(struct drm_device *dev,
729			   struct drm_file *file_priv,
730			   struct drm_pending_event *p,
731			   struct drm_event *e)
732{
733	unsigned long flags;
734	int ret;
735
736	spin_lock_irqsave(&dev->event_lock, flags);
737	ret = drm_event_reserve_init_locked(dev, file_priv, p, e);
738	spin_unlock_irqrestore(&dev->event_lock, flags);
739
740	return ret;
741}
742EXPORT_SYMBOL(drm_event_reserve_init);
743
744/**
745 * drm_event_cancel_free - free a DRM event and release its space
746 * @dev: DRM device
747 * @p: tracking structure for the pending event
748 *
749 * This function frees the event @p initialized with drm_event_reserve_init()
750 * and releases any allocated space. It is used to cancel an event when the
751 * nonblocking operation could not be submitted and needed to be aborted.
752 */
753void drm_event_cancel_free(struct drm_device *dev,
754			   struct drm_pending_event *p)
755{
756	unsigned long flags;
757
758	spin_lock_irqsave(&dev->event_lock, flags);
759	if (p->file_priv) {
760		p->file_priv->event_space += p->event->length;
761		list_del(&p->pending_link);
762	}
763	spin_unlock_irqrestore(&dev->event_lock, flags);
764
765	if (p->fence)
766		dma_fence_put(p->fence);
767
768	kfree(p);
769}
770EXPORT_SYMBOL(drm_event_cancel_free);
771
772static void drm_send_event_helper(struct drm_device *dev,
773			   struct drm_pending_event *e, ktime_t timestamp)
774{
775	assert_spin_locked(&dev->event_lock);
776
777	if (e->completion) {
778		complete_all(e->completion);
779		e->completion_release(e->completion);
780		e->completion = NULL;
781	}
782
783	if (e->fence) {
784		if (timestamp)
785			dma_fence_signal_timestamp(e->fence, timestamp);
786		else
787			dma_fence_signal(e->fence);
788		dma_fence_put(e->fence);
789	}
790
791	if (!e->file_priv) {
792		kfree(e);
793		return;
794	}
795
796	list_del(&e->pending_link);
797	list_add_tail(&e->link,
798		      &e->file_priv->event_list);
799	wake_up_interruptible_poll(&e->file_priv->event_wait,
800		EPOLLIN | EPOLLRDNORM);
801}
802
803/**
804 * drm_send_event_timestamp_locked - send DRM event to file descriptor
805 * @dev: DRM device
806 * @e: DRM event to deliver
807 * @timestamp: timestamp to set for the fence event in kernel's CLOCK_MONOTONIC
808 * time domain
809 *
810 * This function sends the event @e, initialized with drm_event_reserve_init(),
811 * to its associated userspace DRM file. Callers must already hold
812 * &drm_device.event_lock.
813 *
814 * Note that the core will take care of unlinking and disarming events when the
815 * corresponding DRM file is closed. Drivers need not worry about whether the
816 * DRM file for this event still exists and can call this function upon
817 * completion of the asynchronous work unconditionally.
818 */
819void drm_send_event_timestamp_locked(struct drm_device *dev,
820				     struct drm_pending_event *e, ktime_t timestamp)
821{
822	drm_send_event_helper(dev, e, timestamp);
823}
824EXPORT_SYMBOL(drm_send_event_timestamp_locked);
825
826/**
827 * drm_send_event_locked - send DRM event to file descriptor
828 * @dev: DRM device
829 * @e: DRM event to deliver
830 *
831 * This function sends the event @e, initialized with drm_event_reserve_init(),
832 * to its associated userspace DRM file. Callers must already hold
833 * &drm_device.event_lock, see drm_send_event() for the unlocked version.
834 *
835 * Note that the core will take care of unlinking and disarming events when the
836 * corresponding DRM file is closed. Drivers need not worry about whether the
837 * DRM file for this event still exists and can call this function upon
838 * completion of the asynchronous work unconditionally.
839 */
840void drm_send_event_locked(struct drm_device *dev, struct drm_pending_event *e)
841{
842	drm_send_event_helper(dev, e, 0);
843}
844EXPORT_SYMBOL(drm_send_event_locked);
845
846/**
847 * drm_send_event - send DRM event to file descriptor
848 * @dev: DRM device
849 * @e: DRM event to deliver
850 *
851 * This function sends the event @e, initialized with drm_event_reserve_init(),
852 * to its associated userspace DRM file. This function acquires
853 * &drm_device.event_lock, see drm_send_event_locked() for callers which already
854 * hold this lock.
855 *
856 * Note that the core will take care of unlinking and disarming events when the
857 * corresponding DRM file is closed. Drivers need not worry about whether the
858 * DRM file for this event still exists and can call this function upon
859 * completion of the asynchronous work unconditionally.
860 */
861void drm_send_event(struct drm_device *dev, struct drm_pending_event *e)
862{
863	unsigned long irqflags;
864
865	spin_lock_irqsave(&dev->event_lock, irqflags);
866	drm_send_event_helper(dev, e, 0);
867	spin_unlock_irqrestore(&dev->event_lock, irqflags);
868}
869EXPORT_SYMBOL(drm_send_event);
870
871/**
872 * mock_drm_getfile - Create a new struct file for the drm device
873 * @minor: drm minor to wrap (e.g. #drm_device.primary)
874 * @flags: file creation mode (O_RDWR etc)
875 *
876 * This create a new struct file that wraps a DRM file context around a
877 * DRM minor. This mimicks userspace opening e.g. /dev/dri/card0, but without
878 * invoking userspace. The struct file may be operated on using its f_op
879 * (the drm_device.driver.fops) to mimick userspace operations, or be supplied
880 * to userspace facing functions as an internal/anonymous client.
881 *
882 * RETURNS:
883 * Pointer to newly created struct file, ERR_PTR on failure.
884 */
885struct file *mock_drm_getfile(struct drm_minor *minor, unsigned int flags)
886{
887	struct drm_device *dev = minor->dev;
888	struct drm_file *priv;
889	struct file *file;
890
891	priv = drm_file_alloc(minor);
892	if (IS_ERR(priv))
893		return ERR_CAST(priv);
894
895	file = anon_inode_getfile("drm", dev->driver->fops, priv, flags);
896	if (IS_ERR(file)) {
897		drm_file_free(priv);
898		return file;
899	}
900
901	/* Everyone shares a single global address space */
902	file->f_mapping = dev->anon_inode->i_mapping;
903
904	drm_dev_get(dev);
905	priv->filp = file;
906
907	return file;
908}
909EXPORT_SYMBOL_FOR_TESTS_ONLY(mock_drm_getfile);