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1 /*
2  * Created: Fri Jan 19 10:48:35 2001 by faith@acm.org
3  *
4  * Copyright 2001 VA Linux Systems, Inc., Sunnyvale, California.
5  * All Rights Reserved.
6  *
7  * Author Rickard E. (Rik) Faith <faith@valinux.com>
8  *
9  * Permission is hereby granted, free of charge, to any person obtaining a
10  * copy of this software and associated documentation files (the "Software"),
11  * to deal in the Software without restriction, including without limitation
12  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
13  * and/or sell copies of the Software, and to permit persons to whom the
14  * Software is furnished to do so, subject to the following conditions:
15  *
16  * The above copyright notice and this permission notice (including the next
17  * paragraph) shall be included in all copies or substantial portions of the
18  * Software.
19  *
20  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
21  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
22  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
23  * PRECISION INSIGHT AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
24  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
25  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
26  * DEALINGS IN THE SOFTWARE.
27  */
28 
29 #include <linux/debugfs.h>
30 #include <linux/fs.h>
31 #include <linux/module.h>
32 #include <linux/moduleparam.h>
33 #include <linux/mount.h>
34 #include <linux/slab.h>
35 #include <drm/drmP.h>
36 #include <drm/drm_core.h>
37 #include "drm_legacy.h"
38 #include "drm_internal.h"
39 
40 unsigned int drm_debug = 0;	/* bitmask of DRM_UT_x */
41 EXPORT_SYMBOL(drm_debug);
42 
43 MODULE_AUTHOR(CORE_AUTHOR);
44 MODULE_DESCRIPTION(CORE_DESC);
45 MODULE_LICENSE("GPL and additional rights");
46 MODULE_PARM_DESC(debug, "Enable debug output");
47 MODULE_PARM_DESC(vblankoffdelay, "Delay until vblank irq auto-disable [msecs] (0: never disable, <0: disable immediately)");
48 MODULE_PARM_DESC(timestamp_precision_usec, "Max. error on timestamps [usecs]");
49 MODULE_PARM_DESC(timestamp_monotonic, "Use monotonic timestamps");
50 
51 module_param_named(debug, drm_debug, int, 0600);
52 
53 static DEFINE_SPINLOCK(drm_minor_lock);
54 static struct idr drm_minors_idr;
55 
56 static struct dentry *drm_debugfs_root;
57 
drm_err(const char * format,...)58 void drm_err(const char *format, ...)
59 {
60 	struct va_format vaf;
61 	va_list args;
62 
63 	va_start(args, format);
64 
65 	vaf.fmt = format;
66 	vaf.va = &args;
67 
68 	printk(KERN_ERR "[" DRM_NAME ":%ps] *ERROR* %pV",
69 	       __builtin_return_address(0), &vaf);
70 
71 	va_end(args);
72 }
73 EXPORT_SYMBOL(drm_err);
74 
drm_ut_debug_printk(const char * function_name,const char * format,...)75 void drm_ut_debug_printk(const char *function_name, const char *format, ...)
76 {
77 	struct va_format vaf;
78 	va_list args;
79 
80 	va_start(args, format);
81 	vaf.fmt = format;
82 	vaf.va = &args;
83 
84 	printk(KERN_DEBUG "[" DRM_NAME ":%s] %pV", function_name, &vaf);
85 
86 	va_end(args);
87 }
88 EXPORT_SYMBOL(drm_ut_debug_printk);
89 
drm_master_create(struct drm_minor * minor)90 struct drm_master *drm_master_create(struct drm_minor *minor)
91 {
92 	struct drm_master *master;
93 
94 	master = kzalloc(sizeof(*master), GFP_KERNEL);
95 	if (!master)
96 		return NULL;
97 
98 	kref_init(&master->refcount);
99 	spin_lock_init(&master->lock.spinlock);
100 	init_waitqueue_head(&master->lock.lock_queue);
101 	idr_init(&master->magic_map);
102 	master->minor = minor;
103 
104 	return master;
105 }
106 
drm_master_get(struct drm_master * master)107 struct drm_master *drm_master_get(struct drm_master *master)
108 {
109 	kref_get(&master->refcount);
110 	return master;
111 }
112 EXPORT_SYMBOL(drm_master_get);
113 
drm_master_destroy(struct kref * kref)114 static void drm_master_destroy(struct kref *kref)
115 {
116 	struct drm_master *master = container_of(kref, struct drm_master, refcount);
117 	struct drm_device *dev = master->minor->dev;
118 	struct drm_map_list *r_list, *list_temp;
119 
120 	mutex_lock(&dev->struct_mutex);
121 	if (dev->driver->master_destroy)
122 		dev->driver->master_destroy(dev, master);
123 
124 	list_for_each_entry_safe(r_list, list_temp, &dev->maplist, head) {
125 		if (r_list->master == master) {
126 			drm_legacy_rmmap_locked(dev, r_list->map);
127 			r_list = NULL;
128 		}
129 	}
130 	mutex_unlock(&dev->struct_mutex);
131 
132 	idr_destroy(&master->magic_map);
133 	kfree(master->unique);
134 	kfree(master);
135 }
136 
drm_master_put(struct drm_master ** master)137 void drm_master_put(struct drm_master **master)
138 {
139 	kref_put(&(*master)->refcount, drm_master_destroy);
140 	*master = NULL;
141 }
142 EXPORT_SYMBOL(drm_master_put);
143 
drm_setmaster_ioctl(struct drm_device * dev,void * data,struct drm_file * file_priv)144 int drm_setmaster_ioctl(struct drm_device *dev, void *data,
145 			struct drm_file *file_priv)
146 {
147 	int ret = 0;
148 
149 	mutex_lock(&dev->master_mutex);
150 	if (file_priv->is_master)
151 		goto out_unlock;
152 
153 	if (file_priv->minor->master) {
154 		ret = -EINVAL;
155 		goto out_unlock;
156 	}
157 
158 	if (!file_priv->master) {
159 		ret = -EINVAL;
160 		goto out_unlock;
161 	}
162 
163 	if (!file_priv->allowed_master) {
164 		ret = drm_new_set_master(dev, file_priv);
165 		goto out_unlock;
166 	}
167 
168 	file_priv->minor->master = drm_master_get(file_priv->master);
169 	file_priv->is_master = 1;
170 	if (dev->driver->master_set) {
171 		ret = dev->driver->master_set(dev, file_priv, false);
172 		if (unlikely(ret != 0)) {
173 			file_priv->is_master = 0;
174 			drm_master_put(&file_priv->minor->master);
175 		}
176 	}
177 
178 out_unlock:
179 	mutex_unlock(&dev->master_mutex);
180 	return ret;
181 }
182 
drm_dropmaster_ioctl(struct drm_device * dev,void * data,struct drm_file * file_priv)183 int drm_dropmaster_ioctl(struct drm_device *dev, void *data,
184 			 struct drm_file *file_priv)
185 {
186 	int ret = -EINVAL;
187 
188 	mutex_lock(&dev->master_mutex);
189 	if (!file_priv->is_master)
190 		goto out_unlock;
191 
192 	if (!file_priv->minor->master)
193 		goto out_unlock;
194 
195 	ret = 0;
196 	if (dev->driver->master_drop)
197 		dev->driver->master_drop(dev, file_priv, false);
198 	drm_master_put(&file_priv->minor->master);
199 	file_priv->is_master = 0;
200 
201 out_unlock:
202 	mutex_unlock(&dev->master_mutex);
203 	return ret;
204 }
205 
206 /*
207  * DRM Minors
208  * A DRM device can provide several char-dev interfaces on the DRM-Major. Each
209  * of them is represented by a drm_minor object. Depending on the capabilities
210  * of the device-driver, different interfaces are registered.
211  *
212  * Minors can be accessed via dev->$minor_name. This pointer is either
213  * NULL or a valid drm_minor pointer and stays valid as long as the device is
214  * valid. This means, DRM minors have the same life-time as the underlying
215  * device. However, this doesn't mean that the minor is active. Minors are
216  * registered and unregistered dynamically according to device-state.
217  */
218 
drm_minor_get_slot(struct drm_device * dev,unsigned int type)219 static struct drm_minor **drm_minor_get_slot(struct drm_device *dev,
220 					     unsigned int type)
221 {
222 	switch (type) {
223 	case DRM_MINOR_LEGACY:
224 		return &dev->primary;
225 	case DRM_MINOR_RENDER:
226 		return &dev->render;
227 	case DRM_MINOR_CONTROL:
228 		return &dev->control;
229 	default:
230 		return NULL;
231 	}
232 }
233 
drm_minor_alloc(struct drm_device * dev,unsigned int type)234 static int drm_minor_alloc(struct drm_device *dev, unsigned int type)
235 {
236 	struct drm_minor *minor;
237 	unsigned long flags;
238 	int r;
239 
240 	minor = kzalloc(sizeof(*minor), GFP_KERNEL);
241 	if (!minor)
242 		return -ENOMEM;
243 
244 	minor->type = type;
245 	minor->dev = dev;
246 
247 	idr_preload(GFP_KERNEL);
248 	spin_lock_irqsave(&drm_minor_lock, flags);
249 	r = idr_alloc(&drm_minors_idr,
250 		      NULL,
251 		      64 * type,
252 		      64 * (type + 1),
253 		      GFP_NOWAIT);
254 	spin_unlock_irqrestore(&drm_minor_lock, flags);
255 	idr_preload_end();
256 
257 	if (r < 0)
258 		goto err_free;
259 
260 	minor->index = r;
261 
262 	minor->kdev = drm_sysfs_minor_alloc(minor);
263 	if (IS_ERR(minor->kdev)) {
264 		r = PTR_ERR(minor->kdev);
265 		goto err_index;
266 	}
267 
268 	*drm_minor_get_slot(dev, type) = minor;
269 	return 0;
270 
271 err_index:
272 	spin_lock_irqsave(&drm_minor_lock, flags);
273 	idr_remove(&drm_minors_idr, minor->index);
274 	spin_unlock_irqrestore(&drm_minor_lock, flags);
275 err_free:
276 	kfree(minor);
277 	return r;
278 }
279 
drm_minor_free(struct drm_device * dev,unsigned int type)280 static void drm_minor_free(struct drm_device *dev, unsigned int type)
281 {
282 	struct drm_minor **slot, *minor;
283 	unsigned long flags;
284 
285 	slot = drm_minor_get_slot(dev, type);
286 	minor = *slot;
287 	if (!minor)
288 		return;
289 
290 	put_device(minor->kdev);
291 
292 	spin_lock_irqsave(&drm_minor_lock, flags);
293 	idr_remove(&drm_minors_idr, minor->index);
294 	spin_unlock_irqrestore(&drm_minor_lock, flags);
295 
296 	kfree(minor);
297 	*slot = NULL;
298 }
299 
drm_minor_register(struct drm_device * dev,unsigned int type)300 static int drm_minor_register(struct drm_device *dev, unsigned int type)
301 {
302 	struct drm_minor *minor;
303 	unsigned long flags;
304 	int ret;
305 
306 	DRM_DEBUG("\n");
307 
308 	minor = *drm_minor_get_slot(dev, type);
309 	if (!minor)
310 		return 0;
311 
312 	ret = drm_debugfs_init(minor, minor->index, drm_debugfs_root);
313 	if (ret) {
314 		DRM_ERROR("DRM: Failed to initialize /sys/kernel/debug/dri.\n");
315 		goto err_debugfs;
316 	}
317 
318 	ret = device_add(minor->kdev);
319 	if (ret)
320 		goto err_debugfs;
321 
322 	/* replace NULL with @minor so lookups will succeed from now on */
323 	spin_lock_irqsave(&drm_minor_lock, flags);
324 	idr_replace(&drm_minors_idr, minor, minor->index);
325 	spin_unlock_irqrestore(&drm_minor_lock, flags);
326 
327 	DRM_DEBUG("new minor registered %d\n", minor->index);
328 	return 0;
329 
330 err_debugfs:
331 	drm_debugfs_cleanup(minor);
332 	return ret;
333 }
334 
drm_minor_unregister(struct drm_device * dev,unsigned int type)335 static void drm_minor_unregister(struct drm_device *dev, unsigned int type)
336 {
337 	struct drm_minor *minor;
338 	unsigned long flags;
339 
340 	minor = *drm_minor_get_slot(dev, type);
341 	if (!minor || !device_is_registered(minor->kdev))
342 		return;
343 
344 	/* replace @minor with NULL so lookups will fail from now on */
345 	spin_lock_irqsave(&drm_minor_lock, flags);
346 	idr_replace(&drm_minors_idr, NULL, minor->index);
347 	spin_unlock_irqrestore(&drm_minor_lock, flags);
348 
349 	device_del(minor->kdev);
350 	dev_set_drvdata(minor->kdev, NULL); /* safety belt */
351 	drm_debugfs_cleanup(minor);
352 }
353 
354 /**
355  * drm_minor_acquire - Acquire a DRM minor
356  * @minor_id: Minor ID of the DRM-minor
357  *
358  * Looks up the given minor-ID and returns the respective DRM-minor object. The
359  * refence-count of the underlying device is increased so you must release this
360  * object with drm_minor_release().
361  *
362  * As long as you hold this minor, it is guaranteed that the object and the
363  * minor->dev pointer will stay valid! However, the device may get unplugged and
364  * unregistered while you hold the minor.
365  *
366  * Returns:
367  * Pointer to minor-object with increased device-refcount, or PTR_ERR on
368  * failure.
369  */
drm_minor_acquire(unsigned int minor_id)370 struct drm_minor *drm_minor_acquire(unsigned int minor_id)
371 {
372 	struct drm_minor *minor;
373 	unsigned long flags;
374 
375 	spin_lock_irqsave(&drm_minor_lock, flags);
376 	minor = idr_find(&drm_minors_idr, minor_id);
377 	if (minor)
378 		drm_dev_ref(minor->dev);
379 	spin_unlock_irqrestore(&drm_minor_lock, flags);
380 
381 	if (!minor) {
382 		return ERR_PTR(-ENODEV);
383 	} else if (drm_device_is_unplugged(minor->dev)) {
384 		drm_dev_unref(minor->dev);
385 		return ERR_PTR(-ENODEV);
386 	}
387 
388 	return minor;
389 }
390 
391 /**
392  * drm_minor_release - Release DRM minor
393  * @minor: Pointer to DRM minor object
394  *
395  * Release a minor that was previously acquired via drm_minor_acquire().
396  */
drm_minor_release(struct drm_minor * minor)397 void drm_minor_release(struct drm_minor *minor)
398 {
399 	drm_dev_unref(minor->dev);
400 }
401 
402 /**
403  * DOC: driver instance overview
404  *
405  * A device instance for a drm driver is represented by struct &drm_device. This
406  * is allocated with drm_dev_alloc(), usually from bus-specific ->probe()
407  * callbacks implemented by the driver. The driver then needs to initialize all
408  * the various subsystems for the drm device like memory management, vblank
409  * handling, modesetting support and intial output configuration plus obviously
410  * initialize all the corresponding hardware bits. An important part of this is
411  * also calling drm_dev_set_unique() to set the userspace-visible unique name of
412  * this device instance. Finally when everything is up and running and ready for
413  * userspace the device instance can be published using drm_dev_register().
414  *
415  * There is also deprecated support for initalizing device instances using
416  * bus-specific helpers and the ->load() callback. But due to
417  * backwards-compatibility needs the device instance have to be published too
418  * early, which requires unpretty global locking to make safe and is therefore
419  * only support for existing drivers not yet converted to the new scheme.
420  *
421  * When cleaning up a device instance everything needs to be done in reverse:
422  * First unpublish the device instance with drm_dev_unregister(). Then clean up
423  * any other resources allocated at device initialization and drop the driver's
424  * reference to &drm_device using drm_dev_unref().
425  *
426  * Note that the lifetime rules for &drm_device instance has still a lot of
427  * historical baggage. Hence use the reference counting provided by
428  * drm_dev_ref() and drm_dev_unref() only carefully.
429  *
430  * Also note that embedding of &drm_device is currently not (yet) supported (but
431  * it would be easy to add). Drivers can store driver-private data in the
432  * dev_priv field of &drm_device.
433  */
434 
435 /**
436  * drm_put_dev - Unregister and release a DRM device
437  * @dev: DRM device
438  *
439  * Called at module unload time or when a PCI device is unplugged.
440  *
441  * Cleans up all DRM device, calling drm_lastclose().
442  *
443  * Note: Use of this function is deprecated. It will eventually go away
444  * completely.  Please use drm_dev_unregister() and drm_dev_unref() explicitly
445  * instead to make sure that the device isn't userspace accessible any more
446  * while teardown is in progress, ensuring that userspace can't access an
447  * inconsistent state.
448  */
drm_put_dev(struct drm_device * dev)449 void drm_put_dev(struct drm_device *dev)
450 {
451 	DRM_DEBUG("\n");
452 
453 	if (!dev) {
454 		DRM_ERROR("cleanup called no dev\n");
455 		return;
456 	}
457 
458 	drm_dev_unregister(dev);
459 	drm_dev_unref(dev);
460 }
461 EXPORT_SYMBOL(drm_put_dev);
462 
drm_unplug_dev(struct drm_device * dev)463 void drm_unplug_dev(struct drm_device *dev)
464 {
465 	/* for a USB device */
466 	drm_minor_unregister(dev, DRM_MINOR_LEGACY);
467 	drm_minor_unregister(dev, DRM_MINOR_RENDER);
468 	drm_minor_unregister(dev, DRM_MINOR_CONTROL);
469 
470 	mutex_lock(&drm_global_mutex);
471 
472 	drm_device_set_unplugged(dev);
473 
474 	if (dev->open_count == 0) {
475 		drm_put_dev(dev);
476 	}
477 	mutex_unlock(&drm_global_mutex);
478 }
479 EXPORT_SYMBOL(drm_unplug_dev);
480 
481 /*
482  * DRM internal mount
483  * We want to be able to allocate our own "struct address_space" to control
484  * memory-mappings in VRAM (or stolen RAM, ...). However, core MM does not allow
485  * stand-alone address_space objects, so we need an underlying inode. As there
486  * is no way to allocate an independent inode easily, we need a fake internal
487  * VFS mount-point.
488  *
489  * The drm_fs_inode_new() function allocates a new inode, drm_fs_inode_free()
490  * frees it again. You are allowed to use iget() and iput() to get references to
491  * the inode. But each drm_fs_inode_new() call must be paired with exactly one
492  * drm_fs_inode_free() call (which does not have to be the last iput()).
493  * We use drm_fs_inode_*() to manage our internal VFS mount-point and share it
494  * between multiple inode-users. You could, technically, call
495  * iget() + drm_fs_inode_free() directly after alloc and sometime later do an
496  * iput(), but this way you'd end up with a new vfsmount for each inode.
497  */
498 
499 static int drm_fs_cnt;
500 static struct vfsmount *drm_fs_mnt;
501 
502 static const struct dentry_operations drm_fs_dops = {
503 	.d_dname	= simple_dname,
504 };
505 
506 static const struct super_operations drm_fs_sops = {
507 	.statfs		= simple_statfs,
508 };
509 
drm_fs_mount(struct file_system_type * fs_type,int flags,const char * dev_name,void * data)510 static struct dentry *drm_fs_mount(struct file_system_type *fs_type, int flags,
511 				   const char *dev_name, void *data)
512 {
513 	return mount_pseudo(fs_type,
514 			    "drm:",
515 			    &drm_fs_sops,
516 			    &drm_fs_dops,
517 			    0x010203ff);
518 }
519 
520 static struct file_system_type drm_fs_type = {
521 	.name		= "drm",
522 	.owner		= THIS_MODULE,
523 	.mount		= drm_fs_mount,
524 	.kill_sb	= kill_anon_super,
525 };
526 
drm_fs_inode_new(void)527 static struct inode *drm_fs_inode_new(void)
528 {
529 	struct inode *inode;
530 	int r;
531 
532 	r = simple_pin_fs(&drm_fs_type, &drm_fs_mnt, &drm_fs_cnt);
533 	if (r < 0) {
534 		DRM_ERROR("Cannot mount pseudo fs: %d\n", r);
535 		return ERR_PTR(r);
536 	}
537 
538 	inode = alloc_anon_inode(drm_fs_mnt->mnt_sb);
539 	if (IS_ERR(inode))
540 		simple_release_fs(&drm_fs_mnt, &drm_fs_cnt);
541 
542 	return inode;
543 }
544 
drm_fs_inode_free(struct inode * inode)545 static void drm_fs_inode_free(struct inode *inode)
546 {
547 	if (inode) {
548 		iput(inode);
549 		simple_release_fs(&drm_fs_mnt, &drm_fs_cnt);
550 	}
551 }
552 
553 /**
554  * drm_dev_alloc - Allocate new DRM device
555  * @driver: DRM driver to allocate device for
556  * @parent: Parent device object
557  *
558  * Allocate and initialize a new DRM device. No device registration is done.
559  * Call drm_dev_register() to advertice the device to user space and register it
560  * with other core subsystems. This should be done last in the device
561  * initialization sequence to make sure userspace can't access an inconsistent
562  * state.
563  *
564  * The initial ref-count of the object is 1. Use drm_dev_ref() and
565  * drm_dev_unref() to take and drop further ref-counts.
566  *
567  * Note that for purely virtual devices @parent can be NULL.
568  *
569  * RETURNS:
570  * Pointer to new DRM device, or NULL if out of memory.
571  */
drm_dev_alloc(struct drm_driver * driver,struct device * parent)572 struct drm_device *drm_dev_alloc(struct drm_driver *driver,
573 				 struct device *parent)
574 {
575 	struct drm_device *dev;
576 	int ret;
577 
578 	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
579 	if (!dev)
580 		return NULL;
581 
582 	kref_init(&dev->ref);
583 	dev->dev = parent;
584 	dev->driver = driver;
585 
586 	INIT_LIST_HEAD(&dev->filelist);
587 	INIT_LIST_HEAD(&dev->ctxlist);
588 	INIT_LIST_HEAD(&dev->vmalist);
589 	INIT_LIST_HEAD(&dev->maplist);
590 	INIT_LIST_HEAD(&dev->vblank_event_list);
591 
592 	spin_lock_init(&dev->buf_lock);
593 	spin_lock_init(&dev->event_lock);
594 	mutex_init(&dev->struct_mutex);
595 	mutex_init(&dev->ctxlist_mutex);
596 	mutex_init(&dev->master_mutex);
597 
598 	dev->anon_inode = drm_fs_inode_new();
599 	if (IS_ERR(dev->anon_inode)) {
600 		ret = PTR_ERR(dev->anon_inode);
601 		DRM_ERROR("Cannot allocate anonymous inode: %d\n", ret);
602 		goto err_free;
603 	}
604 
605 	if (drm_core_check_feature(dev, DRIVER_MODESET)) {
606 		ret = drm_minor_alloc(dev, DRM_MINOR_CONTROL);
607 		if (ret)
608 			goto err_minors;
609 
610 		WARN_ON(driver->suspend || driver->resume);
611 	}
612 
613 	if (drm_core_check_feature(dev, DRIVER_RENDER)) {
614 		ret = drm_minor_alloc(dev, DRM_MINOR_RENDER);
615 		if (ret)
616 			goto err_minors;
617 	}
618 
619 	ret = drm_minor_alloc(dev, DRM_MINOR_LEGACY);
620 	if (ret)
621 		goto err_minors;
622 
623 	if (drm_ht_create(&dev->map_hash, 12))
624 		goto err_minors;
625 
626 	drm_legacy_ctxbitmap_init(dev);
627 
628 	if (drm_core_check_feature(dev, DRIVER_GEM)) {
629 		ret = drm_gem_init(dev);
630 		if (ret) {
631 			DRM_ERROR("Cannot initialize graphics execution manager (GEM)\n");
632 			goto err_ctxbitmap;
633 		}
634 	}
635 
636 	return dev;
637 
638 err_ctxbitmap:
639 	drm_legacy_ctxbitmap_cleanup(dev);
640 	drm_ht_remove(&dev->map_hash);
641 err_minors:
642 	drm_minor_free(dev, DRM_MINOR_LEGACY);
643 	drm_minor_free(dev, DRM_MINOR_RENDER);
644 	drm_minor_free(dev, DRM_MINOR_CONTROL);
645 	drm_fs_inode_free(dev->anon_inode);
646 err_free:
647 	mutex_destroy(&dev->master_mutex);
648 	kfree(dev);
649 	return NULL;
650 }
651 EXPORT_SYMBOL(drm_dev_alloc);
652 
drm_dev_release(struct kref * ref)653 static void drm_dev_release(struct kref *ref)
654 {
655 	struct drm_device *dev = container_of(ref, struct drm_device, ref);
656 
657 	if (drm_core_check_feature(dev, DRIVER_GEM))
658 		drm_gem_destroy(dev);
659 
660 	drm_legacy_ctxbitmap_cleanup(dev);
661 	drm_ht_remove(&dev->map_hash);
662 	drm_fs_inode_free(dev->anon_inode);
663 
664 	drm_minor_free(dev, DRM_MINOR_LEGACY);
665 	drm_minor_free(dev, DRM_MINOR_RENDER);
666 	drm_minor_free(dev, DRM_MINOR_CONTROL);
667 
668 	mutex_destroy(&dev->master_mutex);
669 	kfree(dev->unique);
670 	kfree(dev);
671 }
672 
673 /**
674  * drm_dev_ref - Take reference of a DRM device
675  * @dev: device to take reference of or NULL
676  *
677  * This increases the ref-count of @dev by one. You *must* already own a
678  * reference when calling this. Use drm_dev_unref() to drop this reference
679  * again.
680  *
681  * This function never fails. However, this function does not provide *any*
682  * guarantee whether the device is alive or running. It only provides a
683  * reference to the object and the memory associated with it.
684  */
drm_dev_ref(struct drm_device * dev)685 void drm_dev_ref(struct drm_device *dev)
686 {
687 	if (dev)
688 		kref_get(&dev->ref);
689 }
690 EXPORT_SYMBOL(drm_dev_ref);
691 
692 /**
693  * drm_dev_unref - Drop reference of a DRM device
694  * @dev: device to drop reference of or NULL
695  *
696  * This decreases the ref-count of @dev by one. The device is destroyed if the
697  * ref-count drops to zero.
698  */
drm_dev_unref(struct drm_device * dev)699 void drm_dev_unref(struct drm_device *dev)
700 {
701 	if (dev)
702 		kref_put(&dev->ref, drm_dev_release);
703 }
704 EXPORT_SYMBOL(drm_dev_unref);
705 
706 /**
707  * drm_dev_register - Register DRM device
708  * @dev: Device to register
709  * @flags: Flags passed to the driver's .load() function
710  *
711  * Register the DRM device @dev with the system, advertise device to user-space
712  * and start normal device operation. @dev must be allocated via drm_dev_alloc()
713  * previously.
714  *
715  * Never call this twice on any device!
716  *
717  * NOTE: To ensure backward compatibility with existing drivers method this
718  * function calls the ->load() method after registering the device nodes,
719  * creating race conditions. Usage of the ->load() methods is therefore
720  * deprecated, drivers must perform all initialization before calling
721  * drm_dev_register().
722  *
723  * RETURNS:
724  * 0 on success, negative error code on failure.
725  */
drm_dev_register(struct drm_device * dev,unsigned long flags)726 int drm_dev_register(struct drm_device *dev, unsigned long flags)
727 {
728 	int ret;
729 
730 	mutex_lock(&drm_global_mutex);
731 
732 	ret = drm_minor_register(dev, DRM_MINOR_CONTROL);
733 	if (ret)
734 		goto err_minors;
735 
736 	ret = drm_minor_register(dev, DRM_MINOR_RENDER);
737 	if (ret)
738 		goto err_minors;
739 
740 	ret = drm_minor_register(dev, DRM_MINOR_LEGACY);
741 	if (ret)
742 		goto err_minors;
743 
744 	if (dev->driver->load) {
745 		ret = dev->driver->load(dev, flags);
746 		if (ret)
747 			goto err_minors;
748 	}
749 
750 	ret = 0;
751 	goto out_unlock;
752 
753 err_minors:
754 	drm_minor_unregister(dev, DRM_MINOR_LEGACY);
755 	drm_minor_unregister(dev, DRM_MINOR_RENDER);
756 	drm_minor_unregister(dev, DRM_MINOR_CONTROL);
757 out_unlock:
758 	mutex_unlock(&drm_global_mutex);
759 	return ret;
760 }
761 EXPORT_SYMBOL(drm_dev_register);
762 
763 /**
764  * drm_dev_unregister - Unregister DRM device
765  * @dev: Device to unregister
766  *
767  * Unregister the DRM device from the system. This does the reverse of
768  * drm_dev_register() but does not deallocate the device. The caller must call
769  * drm_dev_unref() to drop their final reference.
770  *
771  * This should be called first in the device teardown code to make sure
772  * userspace can't access the device instance any more.
773  */
drm_dev_unregister(struct drm_device * dev)774 void drm_dev_unregister(struct drm_device *dev)
775 {
776 	struct drm_map_list *r_list, *list_temp;
777 
778 	drm_lastclose(dev);
779 
780 	if (dev->driver->unload)
781 		dev->driver->unload(dev);
782 
783 	if (dev->agp)
784 		drm_pci_agp_destroy(dev);
785 
786 	drm_vblank_cleanup(dev);
787 
788 	list_for_each_entry_safe(r_list, list_temp, &dev->maplist, head)
789 		drm_legacy_rmmap(dev, r_list->map);
790 
791 	drm_minor_unregister(dev, DRM_MINOR_LEGACY);
792 	drm_minor_unregister(dev, DRM_MINOR_RENDER);
793 	drm_minor_unregister(dev, DRM_MINOR_CONTROL);
794 }
795 EXPORT_SYMBOL(drm_dev_unregister);
796 
797 /**
798  * drm_dev_set_unique - Set the unique name of a DRM device
799  * @dev: device of which to set the unique name
800  * @fmt: format string for unique name
801  *
802  * Sets the unique name of a DRM device using the specified format string and
803  * a variable list of arguments. Drivers can use this at driver probe time if
804  * the unique name of the devices they drive is static.
805  *
806  * Return: 0 on success or a negative error code on failure.
807  */
drm_dev_set_unique(struct drm_device * dev,const char * fmt,...)808 int drm_dev_set_unique(struct drm_device *dev, const char *fmt, ...)
809 {
810 	va_list ap;
811 
812 	kfree(dev->unique);
813 
814 	va_start(ap, fmt);
815 	dev->unique = kvasprintf(GFP_KERNEL, fmt, ap);
816 	va_end(ap);
817 
818 	return dev->unique ? 0 : -ENOMEM;
819 }
820 EXPORT_SYMBOL(drm_dev_set_unique);
821 
822 /*
823  * DRM Core
824  * The DRM core module initializes all global DRM objects and makes them
825  * available to drivers. Once setup, drivers can probe their respective
826  * devices.
827  * Currently, core management includes:
828  *  - The "DRM-Global" key/value database
829  *  - Global ID management for connectors
830  *  - DRM major number allocation
831  *  - DRM minor management
832  *  - DRM sysfs class
833  *  - DRM debugfs root
834  *
835  * Furthermore, the DRM core provides dynamic char-dev lookups. For each
836  * interface registered on a DRM device, you can request minor numbers from DRM
837  * core. DRM core takes care of major-number management and char-dev
838  * registration. A stub ->open() callback forwards any open() requests to the
839  * registered minor.
840  */
841 
drm_stub_open(struct inode * inode,struct file * filp)842 static int drm_stub_open(struct inode *inode, struct file *filp)
843 {
844 	const struct file_operations *new_fops;
845 	struct drm_minor *minor;
846 	int err;
847 
848 	DRM_DEBUG("\n");
849 
850 	mutex_lock(&drm_global_mutex);
851 	minor = drm_minor_acquire(iminor(inode));
852 	if (IS_ERR(minor)) {
853 		err = PTR_ERR(minor);
854 		goto out_unlock;
855 	}
856 
857 	new_fops = fops_get(minor->dev->driver->fops);
858 	if (!new_fops) {
859 		err = -ENODEV;
860 		goto out_release;
861 	}
862 
863 	replace_fops(filp, new_fops);
864 	if (filp->f_op->open)
865 		err = filp->f_op->open(inode, filp);
866 	else
867 		err = 0;
868 
869 out_release:
870 	drm_minor_release(minor);
871 out_unlock:
872 	mutex_unlock(&drm_global_mutex);
873 	return err;
874 }
875 
876 static const struct file_operations drm_stub_fops = {
877 	.owner = THIS_MODULE,
878 	.open = drm_stub_open,
879 	.llseek = noop_llseek,
880 };
881 
drm_core_init(void)882 static int __init drm_core_init(void)
883 {
884 	int ret = -ENOMEM;
885 
886 	drm_global_init();
887 	drm_connector_ida_init();
888 	idr_init(&drm_minors_idr);
889 
890 	if (register_chrdev(DRM_MAJOR, "drm", &drm_stub_fops))
891 		goto err_p1;
892 
893 	ret = drm_sysfs_init();
894 	if (ret < 0) {
895 		printk(KERN_ERR "DRM: Error creating drm class.\n");
896 		goto err_p2;
897 	}
898 
899 	drm_debugfs_root = debugfs_create_dir("dri", NULL);
900 	if (!drm_debugfs_root) {
901 		DRM_ERROR("Cannot create /sys/kernel/debug/dri\n");
902 		ret = -1;
903 		goto err_p3;
904 	}
905 
906 	DRM_INFO("Initialized %s %d.%d.%d %s\n",
907 		 CORE_NAME, CORE_MAJOR, CORE_MINOR, CORE_PATCHLEVEL, CORE_DATE);
908 	return 0;
909 err_p3:
910 	drm_sysfs_destroy();
911 err_p2:
912 	unregister_chrdev(DRM_MAJOR, "drm");
913 
914 	idr_destroy(&drm_minors_idr);
915 err_p1:
916 	return ret;
917 }
918 
drm_core_exit(void)919 static void __exit drm_core_exit(void)
920 {
921 	debugfs_remove(drm_debugfs_root);
922 	drm_sysfs_destroy();
923 
924 	unregister_chrdev(DRM_MAJOR, "drm");
925 
926 	drm_connector_ida_destroy();
927 	idr_destroy(&drm_minors_idr);
928 }
929 
930 module_init(drm_core_init);
931 module_exit(drm_core_exit);
932