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 #if defined(CONFIG_MMU) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
52 #include <uapi/asm/mman.h>
53 #include <drm/drm_vma_manager.h>
54 #endif
55 
56 /* from BKL pushdown */
57 DEFINE_MUTEX(drm_global_mutex);
58 
drm_dev_needs_global_mutex(struct drm_device * dev)59 bool drm_dev_needs_global_mutex(struct drm_device *dev)
60 {
61 	/*
62 	 * Legacy drivers rely on all kinds of BKL locking semantics, don't
63 	 * bother. They also still need BKL locking for their ioctls, so better
64 	 * safe than sorry.
65 	 */
66 	if (drm_core_check_feature(dev, DRIVER_LEGACY))
67 		return true;
68 
69 	/*
70 	 * The deprecated ->load callback must be called after the driver is
71 	 * already registered. This means such drivers rely on the BKL to make
72 	 * sure an open can't proceed until the driver is actually fully set up.
73 	 * Similar hilarity holds for the unload callback.
74 	 */
75 	if (dev->driver->load || dev->driver->unload)
76 		return true;
77 
78 	/*
79 	 * Drivers with the lastclose callback assume that it's synchronized
80 	 * against concurrent opens, which again needs the BKL. The proper fix
81 	 * is to use the drm_client infrastructure with proper locking for each
82 	 * client.
83 	 */
84 	if (dev->driver->lastclose)
85 		return true;
86 
87 	return false;
88 }
89 
90 /**
91  * DOC: file operations
92  *
93  * Drivers must define the file operations structure that forms the DRM
94  * userspace API entry point, even though most of those operations are
95  * implemented in the DRM core. The resulting &struct file_operations must be
96  * stored in the &drm_driver.fops field. The mandatory functions are drm_open(),
97  * drm_read(), drm_ioctl() and drm_compat_ioctl() if CONFIG_COMPAT is enabled
98  * Note that drm_compat_ioctl will be NULL if CONFIG_COMPAT=n, so there's no
99  * need to sprinkle #ifdef into the code. Drivers which implement private ioctls
100  * that require 32/64 bit compatibility support must provide their own
101  * &file_operations.compat_ioctl handler that processes private ioctls and calls
102  * drm_compat_ioctl() for core ioctls.
103  *
104  * In addition drm_read() and drm_poll() provide support for DRM events. DRM
105  * events are a generic and extensible means to send asynchronous events to
106  * userspace through the file descriptor. They are used to send vblank event and
107  * page flip completions by the KMS API. But drivers can also use it for their
108  * own needs, e.g. to signal completion of rendering.
109  *
110  * For the driver-side event interface see drm_event_reserve_init() and
111  * drm_send_event() as the main starting points.
112  *
113  * The memory mapping implementation will vary depending on how the driver
114  * manages memory. Legacy drivers will use the deprecated drm_legacy_mmap()
115  * function, modern drivers should use one of the provided memory-manager
116  * specific implementations. For GEM-based drivers this is drm_gem_mmap().
117  *
118  * No other file operations are supported by the DRM userspace API. Overall the
119  * following is an example &file_operations structure::
120  *
121  *     static const example_drm_fops = {
122  *             .owner = THIS_MODULE,
123  *             .open = drm_open,
124  *             .release = drm_release,
125  *             .unlocked_ioctl = drm_ioctl,
126  *             .compat_ioctl = drm_compat_ioctl, // NULL if CONFIG_COMPAT=n
127  *             .poll = drm_poll,
128  *             .read = drm_read,
129  *             .llseek = no_llseek,
130  *             .mmap = drm_gem_mmap,
131  *     };
132  *
133  * For plain GEM based drivers there is the DEFINE_DRM_GEM_FOPS() macro, and for
134  * CMA based drivers there is the DEFINE_DRM_GEM_CMA_FOPS() macro to make this
135  * simpler.
136  *
137  * The driver's &file_operations must be stored in &drm_driver.fops.
138  *
139  * For driver-private IOCTL handling see the more detailed discussion in
140  * :ref:`IOCTL support in the userland interfaces chapter<drm_driver_ioctl>`.
141  */
142 
143 /**
144  * drm_file_alloc - allocate file context
145  * @minor: minor to allocate on
146  *
147  * This allocates a new DRM file context. It is not linked into any context and
148  * can be used by the caller freely. Note that the context keeps a pointer to
149  * @minor, so it must be freed before @minor is.
150  *
151  * RETURNS:
152  * Pointer to newly allocated context, ERR_PTR on failure.
153  */
drm_file_alloc(struct drm_minor * minor)154 struct drm_file *drm_file_alloc(struct drm_minor *minor)
155 {
156 	struct drm_device *dev = minor->dev;
157 	struct drm_file *file;
158 	int ret;
159 
160 	file = kzalloc(sizeof(*file), GFP_KERNEL);
161 	if (!file)
162 		return ERR_PTR(-ENOMEM);
163 
164 	file->pid = get_pid(task_pid(current));
165 	file->minor = minor;
166 
167 	/* for compatibility root is always authenticated */
168 	file->authenticated = capable(CAP_SYS_ADMIN);
169 
170 	INIT_LIST_HEAD(&file->lhead);
171 	INIT_LIST_HEAD(&file->fbs);
172 	mutex_init(&file->fbs_lock);
173 	INIT_LIST_HEAD(&file->blobs);
174 	INIT_LIST_HEAD(&file->pending_event_list);
175 	INIT_LIST_HEAD(&file->event_list);
176 	init_waitqueue_head(&file->event_wait);
177 	file->event_space = 4096; /* set aside 4k for event buffer */
178 
179 	spin_lock_init(&file->master_lookup_lock);
180 	mutex_init(&file->event_read_lock);
181 
182 	if (drm_core_check_feature(dev, DRIVER_GEM))
183 		drm_gem_open(dev, file);
184 
185 	if (drm_core_check_feature(dev, DRIVER_SYNCOBJ))
186 		drm_syncobj_open(file);
187 
188 	drm_prime_init_file_private(&file->prime);
189 
190 	if (dev->driver->open) {
191 		ret = dev->driver->open(dev, file);
192 		if (ret < 0)
193 			goto out_prime_destroy;
194 	}
195 
196 	return file;
197 
198 out_prime_destroy:
199 	drm_prime_destroy_file_private(&file->prime);
200 	if (drm_core_check_feature(dev, DRIVER_SYNCOBJ))
201 		drm_syncobj_release(file);
202 	if (drm_core_check_feature(dev, DRIVER_GEM))
203 		drm_gem_release(dev, file);
204 	put_pid(file->pid);
205 	kfree(file);
206 
207 	return ERR_PTR(ret);
208 }
209 
drm_events_release(struct drm_file * file_priv)210 static void drm_events_release(struct drm_file *file_priv)
211 {
212 	struct drm_device *dev = file_priv->minor->dev;
213 	struct drm_pending_event *e, *et;
214 	unsigned long flags;
215 
216 	spin_lock_irqsave(&dev->event_lock, flags);
217 
218 	/* Unlink pending events */
219 	list_for_each_entry_safe(e, et, &file_priv->pending_event_list,
220 				 pending_link) {
221 		list_del(&e->pending_link);
222 		e->file_priv = NULL;
223 	}
224 
225 	/* Remove unconsumed events */
226 	list_for_each_entry_safe(e, et, &file_priv->event_list, link) {
227 		list_del(&e->link);
228 		kfree(e);
229 	}
230 
231 	spin_unlock_irqrestore(&dev->event_lock, flags);
232 }
233 
234 /**
235  * drm_file_free - free file context
236  * @file: context to free, or NULL
237  *
238  * This destroys and deallocates a DRM file context previously allocated via
239  * drm_file_alloc(). The caller must make sure to unlink it from any contexts
240  * before calling this.
241  *
242  * If NULL is passed, this is a no-op.
243  */
drm_file_free(struct drm_file * file)244 void drm_file_free(struct drm_file *file)
245 {
246 	struct drm_device *dev;
247 
248 	if (!file)
249 		return;
250 
251 	dev = file->minor->dev;
252 
253 	DRM_DEBUG("comm=\"%s\", pid=%d, dev=0x%lx, open_count=%d\n",
254 		  current->comm, task_pid_nr(current),
255 		  (long)old_encode_dev(file->minor->kdev->devt),
256 		  atomic_read(&dev->open_count));
257 
258 #ifdef CONFIG_DRM_LEGACY
259 	if (drm_core_check_feature(dev, DRIVER_LEGACY) &&
260 	    dev->driver->preclose)
261 		dev->driver->preclose(dev, file);
262 #endif
263 
264 	if (drm_core_check_feature(dev, DRIVER_LEGACY))
265 		drm_legacy_lock_release(dev, file->filp);
266 
267 	if (drm_core_check_feature(dev, DRIVER_HAVE_DMA))
268 		drm_legacy_reclaim_buffers(dev, file);
269 
270 	drm_events_release(file);
271 
272 	if (drm_core_check_feature(dev, DRIVER_MODESET)) {
273 		drm_fb_release(file);
274 		drm_property_destroy_user_blobs(dev, file);
275 	}
276 
277 	if (drm_core_check_feature(dev, DRIVER_SYNCOBJ))
278 		drm_syncobj_release(file);
279 
280 	if (drm_core_check_feature(dev, DRIVER_GEM))
281 		drm_gem_release(dev, file);
282 
283 	drm_legacy_ctxbitmap_flush(dev, file);
284 
285 	if (drm_is_primary_client(file))
286 		drm_master_release(file);
287 
288 	if (dev->driver->postclose)
289 		dev->driver->postclose(dev, file);
290 
291 	drm_prime_destroy_file_private(&file->prime);
292 
293 	WARN_ON(!list_empty(&file->event_list));
294 
295 	put_pid(file->pid);
296 	kfree(file);
297 }
298 
drm_close_helper(struct file * filp)299 static void drm_close_helper(struct file *filp)
300 {
301 	struct drm_file *file_priv = filp->private_data;
302 	struct drm_device *dev = file_priv->minor->dev;
303 
304 	mutex_lock(&dev->filelist_mutex);
305 	list_del(&file_priv->lhead);
306 	mutex_unlock(&dev->filelist_mutex);
307 
308 	drm_file_free(file_priv);
309 }
310 
311 /*
312  * Check whether DRI will run on this CPU.
313  *
314  * \return non-zero if the DRI will run on this CPU, or zero otherwise.
315  */
drm_cpu_valid(void)316 static int drm_cpu_valid(void)
317 {
318 #if defined(__sparc__) && !defined(__sparc_v9__)
319 	return 0;		/* No cmpxchg before v9 sparc. */
320 #endif
321 	return 1;
322 }
323 
324 /*
325  * Called whenever a process opens a drm node
326  *
327  * \param filp file pointer.
328  * \param minor acquired minor-object.
329  * \return zero on success or a negative number on failure.
330  *
331  * Creates and initializes a drm_file structure for the file private data in \p
332  * filp and add it into the double linked list in \p dev.
333  */
drm_open_helper(struct file * filp,struct drm_minor * minor)334 static int drm_open_helper(struct file *filp, struct drm_minor *minor)
335 {
336 	struct drm_device *dev = minor->dev;
337 	struct drm_file *priv;
338 	int ret;
339 
340 	if (filp->f_flags & O_EXCL)
341 		return -EBUSY;	/* No exclusive opens */
342 	if (!drm_cpu_valid())
343 		return -EINVAL;
344 	if (dev->switch_power_state != DRM_SWITCH_POWER_ON &&
345 	    dev->switch_power_state != DRM_SWITCH_POWER_DYNAMIC_OFF)
346 		return -EINVAL;
347 
348 	DRM_DEBUG("comm=\"%s\", pid=%d, minor=%d\n", current->comm,
349 		  task_pid_nr(current), minor->index);
350 
351 	priv = drm_file_alloc(minor);
352 	if (IS_ERR(priv))
353 		return PTR_ERR(priv);
354 
355 	if (drm_is_primary_client(priv)) {
356 		ret = drm_master_open(priv);
357 		if (ret) {
358 			drm_file_free(priv);
359 			return ret;
360 		}
361 	}
362 
363 	filp->private_data = priv;
364 	filp->f_mode |= FMODE_UNSIGNED_OFFSET;
365 	priv->filp = filp;
366 
367 	mutex_lock(&dev->filelist_mutex);
368 	list_add(&priv->lhead, &dev->filelist);
369 	mutex_unlock(&dev->filelist_mutex);
370 
371 #ifdef CONFIG_DRM_LEGACY
372 #ifdef __alpha__
373 	/*
374 	 * Default the hose
375 	 */
376 	if (!dev->hose) {
377 		struct pci_dev *pci_dev;
378 
379 		pci_dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
380 		if (pci_dev) {
381 			dev->hose = pci_dev->sysdata;
382 			pci_dev_put(pci_dev);
383 		}
384 		if (!dev->hose) {
385 			struct pci_bus *b = list_entry(pci_root_buses.next,
386 				struct pci_bus, node);
387 			if (b)
388 				dev->hose = b->sysdata;
389 		}
390 	}
391 #endif
392 #endif
393 
394 	return 0;
395 }
396 
397 /**
398  * drm_open - open method for DRM file
399  * @inode: device inode
400  * @filp: file pointer.
401  *
402  * This function must be used by drivers as their &file_operations.open method.
403  * It looks up the correct DRM device and instantiates all the per-file
404  * resources for it. It also calls the &drm_driver.open driver callback.
405  *
406  * RETURNS:
407  *
408  * 0 on success or negative errno value on failure.
409  */
drm_open(struct inode * inode,struct file * filp)410 int drm_open(struct inode *inode, struct file *filp)
411 {
412 	struct drm_device *dev;
413 	struct drm_minor *minor;
414 	int retcode;
415 	int need_setup = 0;
416 
417 	minor = drm_minor_acquire(iminor(inode));
418 	if (IS_ERR(minor))
419 		return PTR_ERR(minor);
420 
421 	dev = minor->dev;
422 	if (drm_dev_needs_global_mutex(dev))
423 		mutex_lock(&drm_global_mutex);
424 
425 	if (!atomic_fetch_inc(&dev->open_count))
426 		need_setup = 1;
427 
428 	/* share address_space across all char-devs of a single device */
429 	filp->f_mapping = dev->anon_inode->i_mapping;
430 
431 	retcode = drm_open_helper(filp, minor);
432 	if (retcode)
433 		goto err_undo;
434 	if (need_setup) {
435 		retcode = drm_legacy_setup(dev);
436 		if (retcode) {
437 			drm_close_helper(filp);
438 			goto err_undo;
439 		}
440 	}
441 
442 	if (drm_dev_needs_global_mutex(dev))
443 		mutex_unlock(&drm_global_mutex);
444 
445 	return 0;
446 
447 err_undo:
448 	atomic_dec(&dev->open_count);
449 	if (drm_dev_needs_global_mutex(dev))
450 		mutex_unlock(&drm_global_mutex);
451 	drm_minor_release(minor);
452 	return retcode;
453 }
454 EXPORT_SYMBOL(drm_open);
455 
drm_lastclose(struct drm_device * dev)456 void drm_lastclose(struct drm_device * dev)
457 {
458 	DRM_DEBUG("\n");
459 
460 	if (dev->driver->lastclose)
461 		dev->driver->lastclose(dev);
462 	DRM_DEBUG("driver lastclose completed\n");
463 
464 	if (drm_core_check_feature(dev, DRIVER_LEGACY))
465 		drm_legacy_dev_reinit(dev);
466 
467 	drm_client_dev_restore(dev);
468 }
469 
470 /**
471  * drm_release - release method for DRM file
472  * @inode: device inode
473  * @filp: file pointer.
474  *
475  * This function must be used by drivers as their &file_operations.release
476  * method. It frees any resources associated with the open file, and calls the
477  * &drm_driver.postclose driver callback. If this is the last open file for the
478  * DRM device also proceeds to call the &drm_driver.lastclose driver callback.
479  *
480  * RETURNS:
481  *
482  * Always succeeds and returns 0.
483  */
drm_release(struct inode * inode,struct file * filp)484 int drm_release(struct inode *inode, struct file *filp)
485 {
486 	struct drm_file *file_priv = filp->private_data;
487 	struct drm_minor *minor = file_priv->minor;
488 	struct drm_device *dev = minor->dev;
489 
490 	if (drm_dev_needs_global_mutex(dev))
491 		mutex_lock(&drm_global_mutex);
492 
493 	DRM_DEBUG("open_count = %d\n", atomic_read(&dev->open_count));
494 
495 	drm_close_helper(filp);
496 
497 	if (atomic_dec_and_test(&dev->open_count))
498 		drm_lastclose(dev);
499 
500 	if (drm_dev_needs_global_mutex(dev))
501 		mutex_unlock(&drm_global_mutex);
502 
503 	drm_minor_release(minor);
504 
505 	return 0;
506 }
507 EXPORT_SYMBOL(drm_release);
508 
509 /**
510  * drm_release_noglobal - release method for DRM file
511  * @inode: device inode
512  * @filp: file pointer.
513  *
514  * This function may be used by drivers as their &file_operations.release
515  * method. It frees any resources associated with the open file prior to taking
516  * the drm_global_mutex, which then calls the &drm_driver.postclose driver
517  * callback. If this is the last open file for the DRM device also proceeds to
518  * call the &drm_driver.lastclose driver callback.
519  *
520  * RETURNS:
521  *
522  * Always succeeds and returns 0.
523  */
drm_release_noglobal(struct inode * inode,struct file * filp)524 int drm_release_noglobal(struct inode *inode, struct file *filp)
525 {
526 	struct drm_file *file_priv = filp->private_data;
527 	struct drm_minor *minor = file_priv->minor;
528 	struct drm_device *dev = minor->dev;
529 
530 	drm_close_helper(filp);
531 
532 	if (atomic_dec_and_mutex_lock(&dev->open_count, &drm_global_mutex)) {
533 		drm_lastclose(dev);
534 		mutex_unlock(&drm_global_mutex);
535 	}
536 
537 	drm_minor_release(minor);
538 
539 	return 0;
540 }
541 EXPORT_SYMBOL(drm_release_noglobal);
542 
543 /**
544  * drm_read - read method for DRM file
545  * @filp: file pointer
546  * @buffer: userspace destination pointer for the read
547  * @count: count in bytes to read
548  * @offset: offset to read
549  *
550  * This function must be used by drivers as their &file_operations.read
551  * method if they use DRM events for asynchronous signalling to userspace.
552  * Since events are used by the KMS API for vblank and page flip completion this
553  * means all modern display drivers must use it.
554  *
555  * @offset is ignored, DRM events are read like a pipe. Therefore drivers also
556  * must set the &file_operation.llseek to no_llseek(). Polling support is
557  * provided by drm_poll().
558  *
559  * This function will only ever read a full event. Therefore userspace must
560  * supply a big enough buffer to fit any event to ensure forward progress. Since
561  * the maximum event space is currently 4K it's recommended to just use that for
562  * safety.
563  *
564  * RETURNS:
565  *
566  * Number of bytes read (always aligned to full events, and can be 0) or a
567  * negative error code on failure.
568  */
drm_read(struct file * filp,char __user * buffer,size_t count,loff_t * offset)569 ssize_t drm_read(struct file *filp, char __user *buffer,
570 		 size_t count, loff_t *offset)
571 {
572 	struct drm_file *file_priv = filp->private_data;
573 	struct drm_device *dev = file_priv->minor->dev;
574 	ssize_t ret;
575 
576 	ret = mutex_lock_interruptible(&file_priv->event_read_lock);
577 	if (ret)
578 		return ret;
579 
580 	for (;;) {
581 		struct drm_pending_event *e = NULL;
582 
583 		spin_lock_irq(&dev->event_lock);
584 		if (!list_empty(&file_priv->event_list)) {
585 			e = list_first_entry(&file_priv->event_list,
586 					struct drm_pending_event, link);
587 			file_priv->event_space += e->event->length;
588 			list_del(&e->link);
589 		}
590 		spin_unlock_irq(&dev->event_lock);
591 
592 		if (e == NULL) {
593 			if (ret)
594 				break;
595 
596 			if (filp->f_flags & O_NONBLOCK) {
597 				ret = -EAGAIN;
598 				break;
599 			}
600 
601 			mutex_unlock(&file_priv->event_read_lock);
602 			ret = wait_event_interruptible(file_priv->event_wait,
603 						       !list_empty(&file_priv->event_list));
604 			if (ret >= 0)
605 				ret = mutex_lock_interruptible(&file_priv->event_read_lock);
606 			if (ret)
607 				return ret;
608 		} else {
609 			unsigned length = e->event->length;
610 
611 			if (length > count - ret) {
612 put_back_event:
613 				spin_lock_irq(&dev->event_lock);
614 				file_priv->event_space -= length;
615 				list_add(&e->link, &file_priv->event_list);
616 				spin_unlock_irq(&dev->event_lock);
617 				wake_up_interruptible_poll(&file_priv->event_wait,
618 					EPOLLIN | EPOLLRDNORM);
619 				break;
620 			}
621 
622 			if (copy_to_user(buffer + ret, e->event, length)) {
623 				if (ret == 0)
624 					ret = -EFAULT;
625 				goto put_back_event;
626 			}
627 
628 			ret += length;
629 			kfree(e);
630 		}
631 	}
632 	mutex_unlock(&file_priv->event_read_lock);
633 
634 	return ret;
635 }
636 EXPORT_SYMBOL(drm_read);
637 
638 /**
639  * drm_poll - poll method for DRM file
640  * @filp: file pointer
641  * @wait: poll waiter table
642  *
643  * This function must be used by drivers as their &file_operations.read method
644  * if they use DRM events for asynchronous signalling to userspace.  Since
645  * events are used by the KMS API for vblank and page flip completion this means
646  * all modern display drivers must use it.
647  *
648  * See also drm_read().
649  *
650  * RETURNS:
651  *
652  * Mask of POLL flags indicating the current status of the file.
653  */
drm_poll(struct file * filp,struct poll_table_struct * wait)654 __poll_t drm_poll(struct file *filp, struct poll_table_struct *wait)
655 {
656 	struct drm_file *file_priv = filp->private_data;
657 	__poll_t mask = 0;
658 
659 	poll_wait(filp, &file_priv->event_wait, wait);
660 
661 	if (!list_empty(&file_priv->event_list))
662 		mask |= EPOLLIN | EPOLLRDNORM;
663 
664 	return mask;
665 }
666 EXPORT_SYMBOL(drm_poll);
667 
668 /**
669  * drm_event_reserve_init_locked - 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  * This is the locked version of drm_event_reserve_init() for callers which
686  * already hold &drm_device.event_lock.
687  *
688  * RETURNS:
689  *
690  * 0 on success or a negative error code on failure.
691  */
drm_event_reserve_init_locked(struct drm_device * dev,struct drm_file * file_priv,struct drm_pending_event * p,struct drm_event * e)692 int drm_event_reserve_init_locked(struct drm_device *dev,
693 				  struct drm_file *file_priv,
694 				  struct drm_pending_event *p,
695 				  struct drm_event *e)
696 {
697 	if (file_priv->event_space < e->length)
698 		return -ENOMEM;
699 
700 	file_priv->event_space -= e->length;
701 
702 	p->event = e;
703 	list_add(&p->pending_link, &file_priv->pending_event_list);
704 	p->file_priv = file_priv;
705 
706 	return 0;
707 }
708 EXPORT_SYMBOL(drm_event_reserve_init_locked);
709 
710 /**
711  * drm_event_reserve_init - init a DRM event and reserve space for it
712  * @dev: DRM device
713  * @file_priv: DRM file private data
714  * @p: tracking structure for the pending event
715  * @e: actual event data to deliver to userspace
716  *
717  * This function prepares the passed in event for eventual delivery. If the event
718  * doesn't get delivered (because the IOCTL fails later on, before queuing up
719  * anything) then the even must be cancelled and freed using
720  * drm_event_cancel_free(). Successfully initialized events should be sent out
721  * using drm_send_event() or drm_send_event_locked() to signal completion of the
722  * asynchronous event to userspace.
723  *
724  * If callers embedded @p into a larger structure it must be allocated with
725  * kmalloc and @p must be the first member element.
726  *
727  * Callers which already hold &drm_device.event_lock should use
728  * drm_event_reserve_init_locked() instead.
729  *
730  * RETURNS:
731  *
732  * 0 on success or a negative error code on failure.
733  */
drm_event_reserve_init(struct drm_device * dev,struct drm_file * file_priv,struct drm_pending_event * p,struct drm_event * e)734 int drm_event_reserve_init(struct drm_device *dev,
735 			   struct drm_file *file_priv,
736 			   struct drm_pending_event *p,
737 			   struct drm_event *e)
738 {
739 	unsigned long flags;
740 	int ret;
741 
742 	spin_lock_irqsave(&dev->event_lock, flags);
743 	ret = drm_event_reserve_init_locked(dev, file_priv, p, e);
744 	spin_unlock_irqrestore(&dev->event_lock, flags);
745 
746 	return ret;
747 }
748 EXPORT_SYMBOL(drm_event_reserve_init);
749 
750 /**
751  * drm_event_cancel_free - free a DRM event and release its space
752  * @dev: DRM device
753  * @p: tracking structure for the pending event
754  *
755  * This function frees the event @p initialized with drm_event_reserve_init()
756  * and releases any allocated space. It is used to cancel an event when the
757  * nonblocking operation could not be submitted and needed to be aborted.
758  */
drm_event_cancel_free(struct drm_device * dev,struct drm_pending_event * p)759 void drm_event_cancel_free(struct drm_device *dev,
760 			   struct drm_pending_event *p)
761 {
762 	unsigned long flags;
763 
764 	spin_lock_irqsave(&dev->event_lock, flags);
765 	if (p->file_priv) {
766 		p->file_priv->event_space += p->event->length;
767 		list_del(&p->pending_link);
768 	}
769 	spin_unlock_irqrestore(&dev->event_lock, flags);
770 
771 	if (p->fence)
772 		dma_fence_put(p->fence);
773 
774 	kfree(p);
775 }
776 EXPORT_SYMBOL(drm_event_cancel_free);
777 
drm_send_event_helper(struct drm_device * dev,struct drm_pending_event * e,ktime_t timestamp)778 static void drm_send_event_helper(struct drm_device *dev,
779 			   struct drm_pending_event *e, ktime_t timestamp)
780 {
781 	assert_spin_locked(&dev->event_lock);
782 
783 	if (e->completion) {
784 		complete_all(e->completion);
785 		e->completion_release(e->completion);
786 		e->completion = NULL;
787 	}
788 
789 	if (e->fence) {
790 		if (timestamp)
791 			dma_fence_signal_timestamp(e->fence, timestamp);
792 		else
793 			dma_fence_signal(e->fence);
794 		dma_fence_put(e->fence);
795 	}
796 
797 	if (!e->file_priv) {
798 		kfree(e);
799 		return;
800 	}
801 
802 	list_del(&e->pending_link);
803 	list_add_tail(&e->link,
804 		      &e->file_priv->event_list);
805 	wake_up_interruptible_poll(&e->file_priv->event_wait,
806 		EPOLLIN | EPOLLRDNORM);
807 }
808 
809 /**
810  * drm_send_event_timestamp_locked - send DRM event to file descriptor
811  * @dev: DRM device
812  * @e: DRM event to deliver
813  * @timestamp: timestamp to set for the fence event in kernel's CLOCK_MONOTONIC
814  * time domain
815  *
816  * This function sends the event @e, initialized with drm_event_reserve_init(),
817  * to its associated userspace DRM file. Callers must already hold
818  * &drm_device.event_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  */
drm_send_event_timestamp_locked(struct drm_device * dev,struct drm_pending_event * e,ktime_t timestamp)825 void drm_send_event_timestamp_locked(struct drm_device *dev,
826 				     struct drm_pending_event *e, ktime_t timestamp)
827 {
828 	drm_send_event_helper(dev, e, timestamp);
829 }
830 EXPORT_SYMBOL(drm_send_event_timestamp_locked);
831 
832 /**
833  * drm_send_event_locked - send DRM event to file descriptor
834  * @dev: DRM device
835  * @e: DRM event to deliver
836  *
837  * This function sends the event @e, initialized with drm_event_reserve_init(),
838  * to its associated userspace DRM file. Callers must already hold
839  * &drm_device.event_lock, see drm_send_event() for the unlocked version.
840  *
841  * Note that the core will take care of unlinking and disarming events when the
842  * corresponding DRM file is closed. Drivers need not worry about whether the
843  * DRM file for this event still exists and can call this function upon
844  * completion of the asynchronous work unconditionally.
845  */
drm_send_event_locked(struct drm_device * dev,struct drm_pending_event * e)846 void drm_send_event_locked(struct drm_device *dev, struct drm_pending_event *e)
847 {
848 	drm_send_event_helper(dev, e, 0);
849 }
850 EXPORT_SYMBOL(drm_send_event_locked);
851 
852 /**
853  * drm_send_event - send DRM event to file descriptor
854  * @dev: DRM device
855  * @e: DRM event to deliver
856  *
857  * This function sends the event @e, initialized with drm_event_reserve_init(),
858  * to its associated userspace DRM file. This function acquires
859  * &drm_device.event_lock, see drm_send_event_locked() for callers which already
860  * hold this lock.
861  *
862  * Note that the core will take care of unlinking and disarming events when the
863  * corresponding DRM file is closed. Drivers need not worry about whether the
864  * DRM file for this event still exists and can call this function upon
865  * completion of the asynchronous work unconditionally.
866  */
drm_send_event(struct drm_device * dev,struct drm_pending_event * e)867 void drm_send_event(struct drm_device *dev, struct drm_pending_event *e)
868 {
869 	unsigned long irqflags;
870 
871 	spin_lock_irqsave(&dev->event_lock, irqflags);
872 	drm_send_event_helper(dev, e, 0);
873 	spin_unlock_irqrestore(&dev->event_lock, irqflags);
874 }
875 EXPORT_SYMBOL(drm_send_event);
876 
877 /**
878  * mock_drm_getfile - Create a new struct file for the drm device
879  * @minor: drm minor to wrap (e.g. #drm_device.primary)
880  * @flags: file creation mode (O_RDWR etc)
881  *
882  * This create a new struct file that wraps a DRM file context around a
883  * DRM minor. This mimicks userspace opening e.g. /dev/dri/card0, but without
884  * invoking userspace. The struct file may be operated on using its f_op
885  * (the drm_device.driver.fops) to mimick userspace operations, or be supplied
886  * to userspace facing functions as an internal/anonymous client.
887  *
888  * RETURNS:
889  * Pointer to newly created struct file, ERR_PTR on failure.
890  */
mock_drm_getfile(struct drm_minor * minor,unsigned int flags)891 struct file *mock_drm_getfile(struct drm_minor *minor, unsigned int flags)
892 {
893 	struct drm_device *dev = minor->dev;
894 	struct drm_file *priv;
895 	struct file *file;
896 
897 	priv = drm_file_alloc(minor);
898 	if (IS_ERR(priv))
899 		return ERR_CAST(priv);
900 
901 	file = anon_inode_getfile("drm", dev->driver->fops, priv, flags);
902 	if (IS_ERR(file)) {
903 		drm_file_free(priv);
904 		return file;
905 	}
906 
907 	/* Everyone shares a single global address space */
908 	file->f_mapping = dev->anon_inode->i_mapping;
909 
910 	drm_dev_get(dev);
911 	priv->filp = file;
912 
913 	return file;
914 }
915 EXPORT_SYMBOL_FOR_TESTS_ONLY(mock_drm_getfile);
916 
917 #ifdef CONFIG_MMU
918 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
919 /*
920  * drm_addr_inflate() attempts to construct an aligned area by inflating
921  * the area size and skipping the unaligned start of the area.
922  * adapted from shmem_get_unmapped_area()
923  */
drm_addr_inflate(unsigned long addr,unsigned long len,unsigned long pgoff,unsigned long flags,unsigned long huge_size)924 static unsigned long drm_addr_inflate(unsigned long addr,
925 				      unsigned long len,
926 				      unsigned long pgoff,
927 				      unsigned long flags,
928 				      unsigned long huge_size)
929 {
930 	unsigned long offset, inflated_len;
931 	unsigned long inflated_addr;
932 	unsigned long inflated_offset;
933 
934 	offset = (pgoff << PAGE_SHIFT) & (huge_size - 1);
935 	if (offset && offset + len < 2 * huge_size)
936 		return addr;
937 	if ((addr & (huge_size - 1)) == offset)
938 		return addr;
939 
940 	inflated_len = len + huge_size - PAGE_SIZE;
941 	if (inflated_len > TASK_SIZE)
942 		return addr;
943 	if (inflated_len < len)
944 		return addr;
945 
946 	inflated_addr = current->mm->get_unmapped_area(NULL, 0, inflated_len,
947 						       0, flags);
948 	if (IS_ERR_VALUE(inflated_addr))
949 		return addr;
950 	if (inflated_addr & ~PAGE_MASK)
951 		return addr;
952 
953 	inflated_offset = inflated_addr & (huge_size - 1);
954 	inflated_addr += offset - inflated_offset;
955 	if (inflated_offset > offset)
956 		inflated_addr += huge_size;
957 
958 	if (inflated_addr > TASK_SIZE - len)
959 		return addr;
960 
961 	return inflated_addr;
962 }
963 
964 /**
965  * drm_get_unmapped_area() - Get an unused user-space virtual memory area
966  * suitable for huge page table entries.
967  * @file: The struct file representing the address space being mmap()'d.
968  * @uaddr: Start address suggested by user-space.
969  * @len: Length of the area.
970  * @pgoff: The page offset into the address space.
971  * @flags: mmap flags
972  * @mgr: The address space manager used by the drm driver. This argument can
973  * probably be removed at some point when all drivers use the same
974  * address space manager.
975  *
976  * This function attempts to find an unused user-space virtual memory area
977  * that can accommodate the size we want to map, and that is properly
978  * aligned to facilitate huge page table entries matching actual
979  * huge pages or huge page aligned memory in buffer objects. Buffer objects
980  * are assumed to start at huge page boundary pfns (io memory) or be
981  * populated by huge pages aligned to the start of the buffer object
982  * (system- or coherent memory). Adapted from shmem_get_unmapped_area.
983  *
984  * Return: aligned user-space address.
985  */
drm_get_unmapped_area(struct file * file,unsigned long uaddr,unsigned long len,unsigned long pgoff,unsigned long flags,struct drm_vma_offset_manager * mgr)986 unsigned long drm_get_unmapped_area(struct file *file,
987 				    unsigned long uaddr, unsigned long len,
988 				    unsigned long pgoff, unsigned long flags,
989 				    struct drm_vma_offset_manager *mgr)
990 {
991 	unsigned long addr;
992 	unsigned long inflated_addr;
993 	struct drm_vma_offset_node *node;
994 
995 	if (len > TASK_SIZE)
996 		return -ENOMEM;
997 
998 	/*
999 	 * @pgoff is the file page-offset the huge page boundaries of
1000 	 * which typically aligns to physical address huge page boundaries.
1001 	 * That's not true for DRM, however, where physical address huge
1002 	 * page boundaries instead are aligned with the offset from
1003 	 * buffer object start. So adjust @pgoff to be the offset from
1004 	 * buffer object start.
1005 	 */
1006 	drm_vma_offset_lock_lookup(mgr);
1007 	node = drm_vma_offset_lookup_locked(mgr, pgoff, 1);
1008 	if (node)
1009 		pgoff -= node->vm_node.start;
1010 	drm_vma_offset_unlock_lookup(mgr);
1011 
1012 	addr = current->mm->get_unmapped_area(file, uaddr, len, pgoff, flags);
1013 	if (IS_ERR_VALUE(addr))
1014 		return addr;
1015 	if (addr & ~PAGE_MASK)
1016 		return addr;
1017 	if (addr > TASK_SIZE - len)
1018 		return addr;
1019 
1020 	if (len < HPAGE_PMD_SIZE)
1021 		return addr;
1022 	if (flags & MAP_FIXED)
1023 		return addr;
1024 	/*
1025 	 * Our priority is to support MAP_SHARED mapped hugely;
1026 	 * and support MAP_PRIVATE mapped hugely too, until it is COWed.
1027 	 * But if caller specified an address hint, respect that as before.
1028 	 */
1029 	if (uaddr)
1030 		return addr;
1031 
1032 	inflated_addr = drm_addr_inflate(addr, len, pgoff, flags,
1033 					 HPAGE_PMD_SIZE);
1034 
1035 	if (IS_ENABLED(CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD) &&
1036 	    len >= HPAGE_PUD_SIZE)
1037 		inflated_addr = drm_addr_inflate(inflated_addr, len, pgoff,
1038 						 flags, HPAGE_PUD_SIZE);
1039 	return inflated_addr;
1040 }
1041 #else /* CONFIG_TRANSPARENT_HUGEPAGE */
drm_get_unmapped_area(struct file * file,unsigned long uaddr,unsigned long len,unsigned long pgoff,unsigned long flags,struct drm_vma_offset_manager * mgr)1042 unsigned long drm_get_unmapped_area(struct file *file,
1043 				    unsigned long uaddr, unsigned long len,
1044 				    unsigned long pgoff, unsigned long flags,
1045 				    struct drm_vma_offset_manager *mgr)
1046 {
1047 	return current->mm->get_unmapped_area(file, uaddr, len, pgoff, flags);
1048 }
1049 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
1050 EXPORT_SYMBOL_GPL(drm_get_unmapped_area);
1051 #endif /* CONFIG_MMU */
1052