xref: /linux/drivers/gpu/drm/drm_file.c (revision 5d666496c24129edeb2bcb500498b87cc64e7f07)
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 #include <linux/vga_switcheroo.h>
42 
43 #include <drm/drm_client.h>
44 #include <drm/drm_drv.h>
45 #include <drm/drm_file.h>
46 #include <drm/drm_gem.h>
47 #include <drm/drm_print.h>
48 
49 #include "drm_crtc_internal.h"
50 #include "drm_internal.h"
51 
52 /* from BKL pushdown */
53 DEFINE_MUTEX(drm_global_mutex);
54 
55 bool drm_dev_needs_global_mutex(struct drm_device *dev)
56 {
57 	/*
58 	 * The deprecated ->load callback must be called after the driver is
59 	 * already registered. This means such drivers rely on the BKL to make
60 	 * sure an open can't proceed until the driver is actually fully set up.
61 	 * Similar hilarity holds for the unload callback.
62 	 */
63 	if (dev->driver->load || dev->driver->unload)
64 		return true;
65 
66 	return false;
67 }
68 
69 /**
70  * DOC: file operations
71  *
72  * Drivers must define the file operations structure that forms the DRM
73  * userspace API entry point, even though most of those operations are
74  * implemented in the DRM core. The resulting &struct file_operations must be
75  * stored in the &drm_driver.fops field. The mandatory functions are drm_open(),
76  * drm_read(), drm_ioctl() and drm_compat_ioctl() if CONFIG_COMPAT is enabled
77  * Note that drm_compat_ioctl will be NULL if CONFIG_COMPAT=n, so there's no
78  * need to sprinkle #ifdef into the code. Drivers which implement private ioctls
79  * that require 32/64 bit compatibility support must provide their own
80  * &file_operations.compat_ioctl handler that processes private ioctls and calls
81  * drm_compat_ioctl() for core ioctls.
82  *
83  * In addition drm_read() and drm_poll() provide support for DRM events. DRM
84  * events are a generic and extensible means to send asynchronous events to
85  * userspace through the file descriptor. They are used to send vblank event and
86  * page flip completions by the KMS API. But drivers can also use it for their
87  * own needs, e.g. to signal completion of rendering.
88  *
89  * For the driver-side event interface see drm_event_reserve_init() and
90  * drm_send_event() as the main starting points.
91  *
92  * The memory mapping implementation will vary depending on how the driver
93  * manages memory. For GEM-based drivers this is drm_gem_mmap().
94  *
95  * No other file operations are supported by the DRM userspace API. Overall the
96  * following is an example &file_operations structure::
97  *
98  *     static const example_drm_fops = {
99  *             .owner = THIS_MODULE,
100  *             .open = drm_open,
101  *             .release = drm_release,
102  *             .unlocked_ioctl = drm_ioctl,
103  *             .compat_ioctl = drm_compat_ioctl, // NULL if CONFIG_COMPAT=n
104  *             .poll = drm_poll,
105  *             .read = drm_read,
106  *             .llseek = no_llseek,
107  *             .mmap = drm_gem_mmap,
108  *     };
109  *
110  * For plain GEM based drivers there is the DEFINE_DRM_GEM_FOPS() macro, and for
111  * DMA based drivers there is the DEFINE_DRM_GEM_DMA_FOPS() macro to make this
112  * simpler.
113  *
114  * The driver's &file_operations must be stored in &drm_driver.fops.
115  *
116  * For driver-private IOCTL handling see the more detailed discussion in
117  * :ref:`IOCTL support in the userland interfaces chapter<drm_driver_ioctl>`.
118  */
119 
120 /**
121  * drm_file_alloc - allocate file context
122  * @minor: minor to allocate on
123  *
124  * This allocates a new DRM file context. It is not linked into any context and
125  * can be used by the caller freely. Note that the context keeps a pointer to
126  * @minor, so it must be freed before @minor is.
127  *
128  * RETURNS:
129  * Pointer to newly allocated context, ERR_PTR on failure.
130  */
131 struct drm_file *drm_file_alloc(struct drm_minor *minor)
132 {
133 	static atomic64_t ident = ATOMIC_INIT(0);
134 	struct drm_device *dev = minor->dev;
135 	struct drm_file *file;
136 	int ret;
137 
138 	file = kzalloc(sizeof(*file), GFP_KERNEL);
139 	if (!file)
140 		return ERR_PTR(-ENOMEM);
141 
142 	/* Get a unique identifier for fdinfo: */
143 	file->client_id = atomic64_inc_return(&ident);
144 	rcu_assign_pointer(file->pid, get_pid(task_tgid(current)));
145 	file->minor = minor;
146 
147 	/* for compatibility root is always authenticated */
148 	file->authenticated = capable(CAP_SYS_ADMIN);
149 
150 	INIT_LIST_HEAD(&file->lhead);
151 	INIT_LIST_HEAD(&file->fbs);
152 	mutex_init(&file->fbs_lock);
153 	INIT_LIST_HEAD(&file->blobs);
154 	INIT_LIST_HEAD(&file->pending_event_list);
155 	INIT_LIST_HEAD(&file->event_list);
156 	init_waitqueue_head(&file->event_wait);
157 	file->event_space = 4096; /* set aside 4k for event buffer */
158 
159 	spin_lock_init(&file->master_lookup_lock);
160 	mutex_init(&file->event_read_lock);
161 
162 	if (drm_core_check_feature(dev, DRIVER_GEM))
163 		drm_gem_open(dev, file);
164 
165 	if (drm_core_check_feature(dev, DRIVER_SYNCOBJ))
166 		drm_syncobj_open(file);
167 
168 	drm_prime_init_file_private(&file->prime);
169 
170 	if (dev->driver->open) {
171 		ret = dev->driver->open(dev, file);
172 		if (ret < 0)
173 			goto out_prime_destroy;
174 	}
175 
176 	return file;
177 
178 out_prime_destroy:
179 	drm_prime_destroy_file_private(&file->prime);
180 	if (drm_core_check_feature(dev, DRIVER_SYNCOBJ))
181 		drm_syncobj_release(file);
182 	if (drm_core_check_feature(dev, DRIVER_GEM))
183 		drm_gem_release(dev, file);
184 	put_pid(rcu_access_pointer(file->pid));
185 	kfree(file);
186 
187 	return ERR_PTR(ret);
188 }
189 
190 static void drm_events_release(struct drm_file *file_priv)
191 {
192 	struct drm_device *dev = file_priv->minor->dev;
193 	struct drm_pending_event *e, *et;
194 	unsigned long flags;
195 
196 	spin_lock_irqsave(&dev->event_lock, flags);
197 
198 	/* Unlink pending events */
199 	list_for_each_entry_safe(e, et, &file_priv->pending_event_list,
200 				 pending_link) {
201 		list_del(&e->pending_link);
202 		e->file_priv = NULL;
203 	}
204 
205 	/* Remove unconsumed events */
206 	list_for_each_entry_safe(e, et, &file_priv->event_list, link) {
207 		list_del(&e->link);
208 		kfree(e);
209 	}
210 
211 	spin_unlock_irqrestore(&dev->event_lock, flags);
212 }
213 
214 /**
215  * drm_file_free - free file context
216  * @file: context to free, or NULL
217  *
218  * This destroys and deallocates a DRM file context previously allocated via
219  * drm_file_alloc(). The caller must make sure to unlink it from any contexts
220  * before calling this.
221  *
222  * If NULL is passed, this is a no-op.
223  */
224 void drm_file_free(struct drm_file *file)
225 {
226 	struct drm_device *dev;
227 
228 	if (!file)
229 		return;
230 
231 	dev = file->minor->dev;
232 
233 	drm_dbg_core(dev, "comm=\"%s\", pid=%d, dev=0x%lx, open_count=%d\n",
234 		     current->comm, task_pid_nr(current),
235 		     (long)old_encode_dev(file->minor->kdev->devt),
236 		     atomic_read(&dev->open_count));
237 
238 	drm_events_release(file);
239 
240 	if (drm_core_check_feature(dev, DRIVER_MODESET)) {
241 		drm_fb_release(file);
242 		drm_property_destroy_user_blobs(dev, file);
243 	}
244 
245 	if (drm_core_check_feature(dev, DRIVER_SYNCOBJ))
246 		drm_syncobj_release(file);
247 
248 	if (drm_core_check_feature(dev, DRIVER_GEM))
249 		drm_gem_release(dev, file);
250 
251 	if (drm_is_primary_client(file))
252 		drm_master_release(file);
253 
254 	if (dev->driver->postclose)
255 		dev->driver->postclose(dev, file);
256 
257 	drm_prime_destroy_file_private(&file->prime);
258 
259 	WARN_ON(!list_empty(&file->event_list));
260 
261 	put_pid(rcu_access_pointer(file->pid));
262 	kfree(file);
263 }
264 
265 static void drm_close_helper(struct file *filp)
266 {
267 	struct drm_file *file_priv = filp->private_data;
268 	struct drm_device *dev = file_priv->minor->dev;
269 
270 	mutex_lock(&dev->filelist_mutex);
271 	list_del(&file_priv->lhead);
272 	mutex_unlock(&dev->filelist_mutex);
273 
274 	drm_file_free(file_priv);
275 }
276 
277 /*
278  * Check whether DRI will run on this CPU.
279  *
280  * \return non-zero if the DRI will run on this CPU, or zero otherwise.
281  */
282 static int drm_cpu_valid(void)
283 {
284 #if defined(__sparc__) && !defined(__sparc_v9__)
285 	return 0;		/* No cmpxchg before v9 sparc. */
286 #endif
287 	return 1;
288 }
289 
290 /*
291  * Called whenever a process opens a drm node
292  *
293  * \param filp file pointer.
294  * \param minor acquired minor-object.
295  * \return zero on success or a negative number on failure.
296  *
297  * Creates and initializes a drm_file structure for the file private data in \p
298  * filp and add it into the double linked list in \p dev.
299  */
300 int drm_open_helper(struct file *filp, struct drm_minor *minor)
301 {
302 	struct drm_device *dev = minor->dev;
303 	struct drm_file *priv;
304 	int ret;
305 
306 	if (filp->f_flags & O_EXCL)
307 		return -EBUSY;	/* No exclusive opens */
308 	if (!drm_cpu_valid())
309 		return -EINVAL;
310 	if (dev->switch_power_state != DRM_SWITCH_POWER_ON &&
311 	    dev->switch_power_state != DRM_SWITCH_POWER_DYNAMIC_OFF)
312 		return -EINVAL;
313 
314 	drm_dbg_core(dev, "comm=\"%s\", pid=%d, minor=%d\n",
315 		     current->comm, task_pid_nr(current), minor->index);
316 
317 	priv = drm_file_alloc(minor);
318 	if (IS_ERR(priv))
319 		return PTR_ERR(priv);
320 
321 	if (drm_is_primary_client(priv)) {
322 		ret = drm_master_open(priv);
323 		if (ret) {
324 			drm_file_free(priv);
325 			return ret;
326 		}
327 	}
328 
329 	filp->private_data = priv;
330 	filp->f_mode |= FMODE_UNSIGNED_OFFSET;
331 	priv->filp = filp;
332 
333 	mutex_lock(&dev->filelist_mutex);
334 	list_add(&priv->lhead, &dev->filelist);
335 	mutex_unlock(&dev->filelist_mutex);
336 
337 	return 0;
338 }
339 
340 /**
341  * drm_open - open method for DRM file
342  * @inode: device inode
343  * @filp: file pointer.
344  *
345  * This function must be used by drivers as their &file_operations.open method.
346  * It looks up the correct DRM device and instantiates all the per-file
347  * resources for it. It also calls the &drm_driver.open driver callback.
348  *
349  * RETURNS:
350  *
351  * 0 on success or negative errno value on failure.
352  */
353 int drm_open(struct inode *inode, struct file *filp)
354 {
355 	struct drm_device *dev;
356 	struct drm_minor *minor;
357 	int retcode;
358 
359 	minor = drm_minor_acquire(iminor(inode));
360 	if (IS_ERR(minor))
361 		return PTR_ERR(minor);
362 
363 	dev = minor->dev;
364 	if (drm_dev_needs_global_mutex(dev))
365 		mutex_lock(&drm_global_mutex);
366 
367 	atomic_fetch_inc(&dev->open_count);
368 
369 	/* share address_space across all char-devs of a single device */
370 	filp->f_mapping = dev->anon_inode->i_mapping;
371 
372 	retcode = drm_open_helper(filp, minor);
373 	if (retcode)
374 		goto err_undo;
375 
376 	if (drm_dev_needs_global_mutex(dev))
377 		mutex_unlock(&drm_global_mutex);
378 
379 	return 0;
380 
381 err_undo:
382 	atomic_dec(&dev->open_count);
383 	if (drm_dev_needs_global_mutex(dev))
384 		mutex_unlock(&drm_global_mutex);
385 	drm_minor_release(minor);
386 	return retcode;
387 }
388 EXPORT_SYMBOL(drm_open);
389 
390 static void drm_lastclose(struct drm_device *dev)
391 {
392 	drm_client_dev_restore(dev);
393 
394 	if (dev_is_pci(dev->dev))
395 		vga_switcheroo_process_delayed_switch();
396 }
397 
398 /**
399  * drm_release - release method for DRM file
400  * @inode: device inode
401  * @filp: file pointer.
402  *
403  * This function must be used by drivers as their &file_operations.release
404  * method. It frees any resources associated with the open file. If this
405  * is the last open file for the DRM device, it also restores the active
406  * in-kernel DRM client.
407  *
408  * RETURNS:
409  *
410  * Always succeeds and returns 0.
411  */
412 int drm_release(struct inode *inode, struct file *filp)
413 {
414 	struct drm_file *file_priv = filp->private_data;
415 	struct drm_minor *minor = file_priv->minor;
416 	struct drm_device *dev = minor->dev;
417 
418 	if (drm_dev_needs_global_mutex(dev))
419 		mutex_lock(&drm_global_mutex);
420 
421 	drm_dbg_core(dev, "open_count = %d\n", atomic_read(&dev->open_count));
422 
423 	drm_close_helper(filp);
424 
425 	if (atomic_dec_and_test(&dev->open_count))
426 		drm_lastclose(dev);
427 
428 	if (drm_dev_needs_global_mutex(dev))
429 		mutex_unlock(&drm_global_mutex);
430 
431 	drm_minor_release(minor);
432 
433 	return 0;
434 }
435 EXPORT_SYMBOL(drm_release);
436 
437 void drm_file_update_pid(struct drm_file *filp)
438 {
439 	struct drm_device *dev;
440 	struct pid *pid, *old;
441 
442 	/*
443 	 * Master nodes need to keep the original ownership in order for
444 	 * drm_master_check_perm to keep working correctly. (See comment in
445 	 * drm_auth.c.)
446 	 */
447 	if (filp->was_master)
448 		return;
449 
450 	pid = task_tgid(current);
451 
452 	/*
453 	 * Quick unlocked check since the model is a single handover followed by
454 	 * exclusive repeated use.
455 	 */
456 	if (pid == rcu_access_pointer(filp->pid))
457 		return;
458 
459 	dev = filp->minor->dev;
460 	mutex_lock(&dev->filelist_mutex);
461 	get_pid(pid);
462 	old = rcu_replace_pointer(filp->pid, pid, 1);
463 	mutex_unlock(&dev->filelist_mutex);
464 
465 	synchronize_rcu();
466 	put_pid(old);
467 }
468 
469 /**
470  * drm_release_noglobal - release method for DRM file
471  * @inode: device inode
472  * @filp: file pointer.
473  *
474  * This function may be used by drivers as their &file_operations.release
475  * method. It frees any resources associated with the open file prior to taking
476  * the drm_global_mutex. If this is the last open file for the DRM device, it
477  * then restores the active in-kernel DRM client.
478  *
479  * RETURNS:
480  *
481  * Always succeeds and returns 0.
482  */
483 int drm_release_noglobal(struct inode *inode, struct file *filp)
484 {
485 	struct drm_file *file_priv = filp->private_data;
486 	struct drm_minor *minor = file_priv->minor;
487 	struct drm_device *dev = minor->dev;
488 
489 	drm_close_helper(filp);
490 
491 	if (atomic_dec_and_mutex_lock(&dev->open_count, &drm_global_mutex)) {
492 		drm_lastclose(dev);
493 		mutex_unlock(&drm_global_mutex);
494 	}
495 
496 	drm_minor_release(minor);
497 
498 	return 0;
499 }
500 EXPORT_SYMBOL(drm_release_noglobal);
501 
502 /**
503  * drm_read - read method for DRM file
504  * @filp: file pointer
505  * @buffer: userspace destination pointer for the read
506  * @count: count in bytes to read
507  * @offset: offset to read
508  *
509  * This function must be used by drivers as their &file_operations.read
510  * method if they use DRM events for asynchronous signalling to userspace.
511  * Since events are used by the KMS API for vblank and page flip completion this
512  * means all modern display drivers must use it.
513  *
514  * @offset is ignored, DRM events are read like a pipe. Polling support is
515  * provided by drm_poll().
516  *
517  * This function will only ever read a full event. Therefore userspace must
518  * supply a big enough buffer to fit any event to ensure forward progress. Since
519  * the maximum event space is currently 4K it's recommended to just use that for
520  * safety.
521  *
522  * RETURNS:
523  *
524  * Number of bytes read (always aligned to full events, and can be 0) or a
525  * negative error code on failure.
526  */
527 ssize_t drm_read(struct file *filp, char __user *buffer,
528 		 size_t count, loff_t *offset)
529 {
530 	struct drm_file *file_priv = filp->private_data;
531 	struct drm_device *dev = file_priv->minor->dev;
532 	ssize_t ret;
533 
534 	ret = mutex_lock_interruptible(&file_priv->event_read_lock);
535 	if (ret)
536 		return ret;
537 
538 	for (;;) {
539 		struct drm_pending_event *e = NULL;
540 
541 		spin_lock_irq(&dev->event_lock);
542 		if (!list_empty(&file_priv->event_list)) {
543 			e = list_first_entry(&file_priv->event_list,
544 					struct drm_pending_event, link);
545 			file_priv->event_space += e->event->length;
546 			list_del(&e->link);
547 		}
548 		spin_unlock_irq(&dev->event_lock);
549 
550 		if (e == NULL) {
551 			if (ret)
552 				break;
553 
554 			if (filp->f_flags & O_NONBLOCK) {
555 				ret = -EAGAIN;
556 				break;
557 			}
558 
559 			mutex_unlock(&file_priv->event_read_lock);
560 			ret = wait_event_interruptible(file_priv->event_wait,
561 						       !list_empty(&file_priv->event_list));
562 			if (ret >= 0)
563 				ret = mutex_lock_interruptible(&file_priv->event_read_lock);
564 			if (ret)
565 				return ret;
566 		} else {
567 			unsigned length = e->event->length;
568 
569 			if (length > count - ret) {
570 put_back_event:
571 				spin_lock_irq(&dev->event_lock);
572 				file_priv->event_space -= length;
573 				list_add(&e->link, &file_priv->event_list);
574 				spin_unlock_irq(&dev->event_lock);
575 				wake_up_interruptible_poll(&file_priv->event_wait,
576 					EPOLLIN | EPOLLRDNORM);
577 				break;
578 			}
579 
580 			if (copy_to_user(buffer + ret, e->event, length)) {
581 				if (ret == 0)
582 					ret = -EFAULT;
583 				goto put_back_event;
584 			}
585 
586 			ret += length;
587 			kfree(e);
588 		}
589 	}
590 	mutex_unlock(&file_priv->event_read_lock);
591 
592 	return ret;
593 }
594 EXPORT_SYMBOL(drm_read);
595 
596 /**
597  * drm_poll - poll method for DRM file
598  * @filp: file pointer
599  * @wait: poll waiter table
600  *
601  * This function must be used by drivers as their &file_operations.read method
602  * if they use DRM events for asynchronous signalling to userspace.  Since
603  * events are used by the KMS API for vblank and page flip completion this means
604  * all modern display drivers must use it.
605  *
606  * See also drm_read().
607  *
608  * RETURNS:
609  *
610  * Mask of POLL flags indicating the current status of the file.
611  */
612 __poll_t drm_poll(struct file *filp, struct poll_table_struct *wait)
613 {
614 	struct drm_file *file_priv = filp->private_data;
615 	__poll_t mask = 0;
616 
617 	poll_wait(filp, &file_priv->event_wait, wait);
618 
619 	if (!list_empty(&file_priv->event_list))
620 		mask |= EPOLLIN | EPOLLRDNORM;
621 
622 	return mask;
623 }
624 EXPORT_SYMBOL(drm_poll);
625 
626 /**
627  * drm_event_reserve_init_locked - init a DRM event and reserve space for it
628  * @dev: DRM device
629  * @file_priv: DRM file private data
630  * @p: tracking structure for the pending event
631  * @e: actual event data to deliver to userspace
632  *
633  * This function prepares the passed in event for eventual delivery. If the event
634  * doesn't get delivered (because the IOCTL fails later on, before queuing up
635  * anything) then the even must be cancelled and freed using
636  * drm_event_cancel_free(). Successfully initialized events should be sent out
637  * using drm_send_event() or drm_send_event_locked() to signal completion of the
638  * asynchronous event to userspace.
639  *
640  * If callers embedded @p into a larger structure it must be allocated with
641  * kmalloc and @p must be the first member element.
642  *
643  * This is the locked version of drm_event_reserve_init() for callers which
644  * already hold &drm_device.event_lock.
645  *
646  * RETURNS:
647  *
648  * 0 on success or a negative error code on failure.
649  */
650 int drm_event_reserve_init_locked(struct drm_device *dev,
651 				  struct drm_file *file_priv,
652 				  struct drm_pending_event *p,
653 				  struct drm_event *e)
654 {
655 	if (file_priv->event_space < e->length)
656 		return -ENOMEM;
657 
658 	file_priv->event_space -= e->length;
659 
660 	p->event = e;
661 	list_add(&p->pending_link, &file_priv->pending_event_list);
662 	p->file_priv = file_priv;
663 
664 	return 0;
665 }
666 EXPORT_SYMBOL(drm_event_reserve_init_locked);
667 
668 /**
669  * drm_event_reserve_init - init a DRM event and reserve space for it
670  * @dev: DRM device
671  * @file_priv: DRM file private data
672  * @p: tracking structure for the pending event
673  * @e: actual event data to deliver to userspace
674  *
675  * This function prepares the passed in event for eventual delivery. If the event
676  * doesn't get delivered (because the IOCTL fails later on, before queuing up
677  * anything) then the even must be cancelled and freed using
678  * drm_event_cancel_free(). Successfully initialized events should be sent out
679  * using drm_send_event() or drm_send_event_locked() to signal completion of the
680  * asynchronous event to userspace.
681  *
682  * If callers embedded @p into a larger structure it must be allocated with
683  * kmalloc and @p must be the first member element.
684  *
685  * Callers which already hold &drm_device.event_lock should use
686  * drm_event_reserve_init_locked() instead.
687  *
688  * RETURNS:
689  *
690  * 0 on success or a negative error code on failure.
691  */
692 int drm_event_reserve_init(struct drm_device *dev,
693 			   struct drm_file *file_priv,
694 			   struct drm_pending_event *p,
695 			   struct drm_event *e)
696 {
697 	unsigned long flags;
698 	int ret;
699 
700 	spin_lock_irqsave(&dev->event_lock, flags);
701 	ret = drm_event_reserve_init_locked(dev, file_priv, p, e);
702 	spin_unlock_irqrestore(&dev->event_lock, flags);
703 
704 	return ret;
705 }
706 EXPORT_SYMBOL(drm_event_reserve_init);
707 
708 /**
709  * drm_event_cancel_free - free a DRM event and release its space
710  * @dev: DRM device
711  * @p: tracking structure for the pending event
712  *
713  * This function frees the event @p initialized with drm_event_reserve_init()
714  * and releases any allocated space. It is used to cancel an event when the
715  * nonblocking operation could not be submitted and needed to be aborted.
716  */
717 void drm_event_cancel_free(struct drm_device *dev,
718 			   struct drm_pending_event *p)
719 {
720 	unsigned long flags;
721 
722 	spin_lock_irqsave(&dev->event_lock, flags);
723 	if (p->file_priv) {
724 		p->file_priv->event_space += p->event->length;
725 		list_del(&p->pending_link);
726 	}
727 	spin_unlock_irqrestore(&dev->event_lock, flags);
728 
729 	if (p->fence)
730 		dma_fence_put(p->fence);
731 
732 	kfree(p);
733 }
734 EXPORT_SYMBOL(drm_event_cancel_free);
735 
736 static void drm_send_event_helper(struct drm_device *dev,
737 			   struct drm_pending_event *e, ktime_t timestamp)
738 {
739 	assert_spin_locked(&dev->event_lock);
740 
741 	if (e->completion) {
742 		complete_all(e->completion);
743 		e->completion_release(e->completion);
744 		e->completion = NULL;
745 	}
746 
747 	if (e->fence) {
748 		if (timestamp)
749 			dma_fence_signal_timestamp(e->fence, timestamp);
750 		else
751 			dma_fence_signal(e->fence);
752 		dma_fence_put(e->fence);
753 	}
754 
755 	if (!e->file_priv) {
756 		kfree(e);
757 		return;
758 	}
759 
760 	list_del(&e->pending_link);
761 	list_add_tail(&e->link,
762 		      &e->file_priv->event_list);
763 	wake_up_interruptible_poll(&e->file_priv->event_wait,
764 		EPOLLIN | EPOLLRDNORM);
765 }
766 
767 /**
768  * drm_send_event_timestamp_locked - send DRM event to file descriptor
769  * @dev: DRM device
770  * @e: DRM event to deliver
771  * @timestamp: timestamp to set for the fence event in kernel's CLOCK_MONOTONIC
772  * time domain
773  *
774  * This function sends the event @e, initialized with drm_event_reserve_init(),
775  * to its associated userspace DRM file. Callers must already hold
776  * &drm_device.event_lock.
777  *
778  * Note that the core will take care of unlinking and disarming events when the
779  * corresponding DRM file is closed. Drivers need not worry about whether the
780  * DRM file for this event still exists and can call this function upon
781  * completion of the asynchronous work unconditionally.
782  */
783 void drm_send_event_timestamp_locked(struct drm_device *dev,
784 				     struct drm_pending_event *e, ktime_t timestamp)
785 {
786 	drm_send_event_helper(dev, e, timestamp);
787 }
788 EXPORT_SYMBOL(drm_send_event_timestamp_locked);
789 
790 /**
791  * drm_send_event_locked - send DRM event to file descriptor
792  * @dev: DRM device
793  * @e: DRM event to deliver
794  *
795  * This function sends the event @e, initialized with drm_event_reserve_init(),
796  * to its associated userspace DRM file. Callers must already hold
797  * &drm_device.event_lock, see drm_send_event() for the unlocked version.
798  *
799  * Note that the core will take care of unlinking and disarming events when the
800  * corresponding DRM file is closed. Drivers need not worry about whether the
801  * DRM file for this event still exists and can call this function upon
802  * completion of the asynchronous work unconditionally.
803  */
804 void drm_send_event_locked(struct drm_device *dev, struct drm_pending_event *e)
805 {
806 	drm_send_event_helper(dev, e, 0);
807 }
808 EXPORT_SYMBOL(drm_send_event_locked);
809 
810 /**
811  * drm_send_event - send DRM event to file descriptor
812  * @dev: DRM device
813  * @e: DRM event to deliver
814  *
815  * This function sends the event @e, initialized with drm_event_reserve_init(),
816  * to its associated userspace DRM file. This function acquires
817  * &drm_device.event_lock, see drm_send_event_locked() for callers which already
818  * hold this lock.
819  *
820  * Note that the core will take care of unlinking and disarming events when the
821  * corresponding DRM file is closed. Drivers need not worry about whether the
822  * DRM file for this event still exists and can call this function upon
823  * completion of the asynchronous work unconditionally.
824  */
825 void drm_send_event(struct drm_device *dev, struct drm_pending_event *e)
826 {
827 	unsigned long irqflags;
828 
829 	spin_lock_irqsave(&dev->event_lock, irqflags);
830 	drm_send_event_helper(dev, e, 0);
831 	spin_unlock_irqrestore(&dev->event_lock, irqflags);
832 }
833 EXPORT_SYMBOL(drm_send_event);
834 
835 static void print_size(struct drm_printer *p, const char *stat,
836 		       const char *region, u64 sz)
837 {
838 	const char *units[] = {"", " KiB", " MiB"};
839 	unsigned u;
840 
841 	for (u = 0; u < ARRAY_SIZE(units) - 1; u++) {
842 		if (sz == 0 || !IS_ALIGNED(sz, SZ_1K))
843 			break;
844 		sz = div_u64(sz, SZ_1K);
845 	}
846 
847 	drm_printf(p, "drm-%s-%s:\t%llu%s\n", stat, region, sz, units[u]);
848 }
849 
850 /**
851  * drm_print_memory_stats - A helper to print memory stats
852  * @p: The printer to print output to
853  * @stats: The collected memory stats
854  * @supported_status: Bitmask of optional stats which are available
855  * @region: The memory region
856  *
857  */
858 void drm_print_memory_stats(struct drm_printer *p,
859 			    const struct drm_memory_stats *stats,
860 			    enum drm_gem_object_status supported_status,
861 			    const char *region)
862 {
863 	print_size(p, "total", region, stats->private + stats->shared);
864 	print_size(p, "shared", region, stats->shared);
865 	print_size(p, "active", region, stats->active);
866 
867 	if (supported_status & DRM_GEM_OBJECT_RESIDENT)
868 		print_size(p, "resident", region, stats->resident);
869 
870 	if (supported_status & DRM_GEM_OBJECT_PURGEABLE)
871 		print_size(p, "purgeable", region, stats->purgeable);
872 }
873 EXPORT_SYMBOL(drm_print_memory_stats);
874 
875 /**
876  * drm_show_memory_stats - Helper to collect and show standard fdinfo memory stats
877  * @p: the printer to print output to
878  * @file: the DRM file
879  *
880  * Helper to iterate over GEM objects with a handle allocated in the specified
881  * file.
882  */
883 void drm_show_memory_stats(struct drm_printer *p, struct drm_file *file)
884 {
885 	struct drm_gem_object *obj;
886 	struct drm_memory_stats status = {};
887 	enum drm_gem_object_status supported_status = 0;
888 	int id;
889 
890 	spin_lock(&file->table_lock);
891 	idr_for_each_entry (&file->object_idr, obj, id) {
892 		enum drm_gem_object_status s = 0;
893 		size_t add_size = (obj->funcs && obj->funcs->rss) ?
894 			obj->funcs->rss(obj) : obj->size;
895 
896 		if (obj->funcs && obj->funcs->status) {
897 			s = obj->funcs->status(obj);
898 			supported_status = DRM_GEM_OBJECT_RESIDENT |
899 					DRM_GEM_OBJECT_PURGEABLE;
900 		}
901 
902 		if (drm_gem_object_is_shared_for_memory_stats(obj)) {
903 			status.shared += obj->size;
904 		} else {
905 			status.private += obj->size;
906 		}
907 
908 		if (s & DRM_GEM_OBJECT_RESIDENT) {
909 			status.resident += add_size;
910 		} else {
911 			/* If already purged or not yet backed by pages, don't
912 			 * count it as purgeable:
913 			 */
914 			s &= ~DRM_GEM_OBJECT_PURGEABLE;
915 		}
916 
917 		if (!dma_resv_test_signaled(obj->resv, dma_resv_usage_rw(true))) {
918 			status.active += add_size;
919 
920 			/* If still active, don't count as purgeable: */
921 			s &= ~DRM_GEM_OBJECT_PURGEABLE;
922 		}
923 
924 		if (s & DRM_GEM_OBJECT_PURGEABLE)
925 			status.purgeable += add_size;
926 	}
927 	spin_unlock(&file->table_lock);
928 
929 	drm_print_memory_stats(p, &status, supported_status, "memory");
930 }
931 EXPORT_SYMBOL(drm_show_memory_stats);
932 
933 /**
934  * drm_show_fdinfo - helper for drm file fops
935  * @m: output stream
936  * @f: the device file instance
937  *
938  * Helper to implement fdinfo, for userspace to query usage stats, etc, of a
939  * process using the GPU.  See also &drm_driver.show_fdinfo.
940  *
941  * For text output format description please see Documentation/gpu/drm-usage-stats.rst
942  */
943 void drm_show_fdinfo(struct seq_file *m, struct file *f)
944 {
945 	struct drm_file *file = f->private_data;
946 	struct drm_device *dev = file->minor->dev;
947 	struct drm_printer p = drm_seq_file_printer(m);
948 
949 	drm_printf(&p, "drm-driver:\t%s\n", dev->driver->name);
950 	drm_printf(&p, "drm-client-id:\t%llu\n", file->client_id);
951 
952 	if (dev_is_pci(dev->dev)) {
953 		struct pci_dev *pdev = to_pci_dev(dev->dev);
954 
955 		drm_printf(&p, "drm-pdev:\t%04x:%02x:%02x.%d\n",
956 			   pci_domain_nr(pdev->bus), pdev->bus->number,
957 			   PCI_SLOT(pdev->devfn), PCI_FUNC(pdev->devfn));
958 	}
959 
960 	if (dev->driver->show_fdinfo)
961 		dev->driver->show_fdinfo(&p, file);
962 }
963 EXPORT_SYMBOL(drm_show_fdinfo);
964 
965 /**
966  * mock_drm_getfile - Create a new struct file for the drm device
967  * @minor: drm minor to wrap (e.g. #drm_device.primary)
968  * @flags: file creation mode (O_RDWR etc)
969  *
970  * This create a new struct file that wraps a DRM file context around a
971  * DRM minor. This mimicks userspace opening e.g. /dev/dri/card0, but without
972  * invoking userspace. The struct file may be operated on using its f_op
973  * (the drm_device.driver.fops) to mimick userspace operations, or be supplied
974  * to userspace facing functions as an internal/anonymous client.
975  *
976  * RETURNS:
977  * Pointer to newly created struct file, ERR_PTR on failure.
978  */
979 struct file *mock_drm_getfile(struct drm_minor *minor, unsigned int flags)
980 {
981 	struct drm_device *dev = minor->dev;
982 	struct drm_file *priv;
983 	struct file *file;
984 
985 	priv = drm_file_alloc(minor);
986 	if (IS_ERR(priv))
987 		return ERR_CAST(priv);
988 
989 	file = anon_inode_getfile("drm", dev->driver->fops, priv, flags);
990 	if (IS_ERR(file)) {
991 		drm_file_free(priv);
992 		return file;
993 	}
994 
995 	/* Everyone shares a single global address space */
996 	file->f_mapping = dev->anon_inode->i_mapping;
997 
998 	drm_dev_get(dev);
999 	priv->filp = file;
1000 
1001 	return file;
1002 }
1003 EXPORT_SYMBOL_FOR_TESTS_ONLY(mock_drm_getfile);
1004