xref: /openbmc/linux/drivers/gpu/drm/drm_drv.c (revision 4f205687)
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 /*
41  * drm_debug: Enable debug output.
42  * Bitmask of DRM_UT_x. See include/drm/drmP.h for details.
43  */
44 unsigned int drm_debug = 0;
45 EXPORT_SYMBOL(drm_debug);
46 
47 MODULE_AUTHOR(CORE_AUTHOR);
48 MODULE_DESCRIPTION(CORE_DESC);
49 MODULE_LICENSE("GPL and additional rights");
50 MODULE_PARM_DESC(debug, "Enable debug output, where each bit enables a debug category.\n"
51 "\t\tBit 0 (0x01) will enable CORE messages (drm core code)\n"
52 "\t\tBit 1 (0x02) will enable DRIVER messages (drm controller code)\n"
53 "\t\tBit 2 (0x04) will enable KMS messages (modesetting code)\n"
54 "\t\tBit 3 (0x08) will enable PRIME messages (prime code)\n"
55 "\t\tBit 4 (0x10) will enable ATOMIC messages (atomic code)\n"
56 "\t\tBit 5 (0x20) will enable VBL messages (vblank code)");
57 module_param_named(debug, drm_debug, int, 0600);
58 
59 static DEFINE_SPINLOCK(drm_minor_lock);
60 static struct idr drm_minors_idr;
61 
62 static struct dentry *drm_debugfs_root;
63 
64 void drm_err(const char *format, ...)
65 {
66 	struct va_format vaf;
67 	va_list args;
68 
69 	va_start(args, format);
70 
71 	vaf.fmt = format;
72 	vaf.va = &args;
73 
74 	printk(KERN_ERR "[" DRM_NAME ":%ps] *ERROR* %pV",
75 	       __builtin_return_address(0), &vaf);
76 
77 	va_end(args);
78 }
79 EXPORT_SYMBOL(drm_err);
80 
81 void drm_ut_debug_printk(const char *function_name, const char *format, ...)
82 {
83 	struct va_format vaf;
84 	va_list args;
85 
86 	va_start(args, format);
87 	vaf.fmt = format;
88 	vaf.va = &args;
89 
90 	printk(KERN_DEBUG "[" DRM_NAME ":%s] %pV", function_name, &vaf);
91 
92 	va_end(args);
93 }
94 EXPORT_SYMBOL(drm_ut_debug_printk);
95 
96 struct drm_master *drm_master_create(struct drm_minor *minor)
97 {
98 	struct drm_master *master;
99 
100 	master = kzalloc(sizeof(*master), GFP_KERNEL);
101 	if (!master)
102 		return NULL;
103 
104 	kref_init(&master->refcount);
105 	spin_lock_init(&master->lock.spinlock);
106 	init_waitqueue_head(&master->lock.lock_queue);
107 	idr_init(&master->magic_map);
108 	master->minor = minor;
109 
110 	return master;
111 }
112 
113 struct drm_master *drm_master_get(struct drm_master *master)
114 {
115 	kref_get(&master->refcount);
116 	return master;
117 }
118 EXPORT_SYMBOL(drm_master_get);
119 
120 static void drm_master_destroy(struct kref *kref)
121 {
122 	struct drm_master *master = container_of(kref, struct drm_master, refcount);
123 	struct drm_device *dev = master->minor->dev;
124 
125 	if (dev->driver->master_destroy)
126 		dev->driver->master_destroy(dev, master);
127 
128 	drm_legacy_master_rmmaps(dev, master);
129 
130 	idr_destroy(&master->magic_map);
131 	kfree(master->unique);
132 	kfree(master);
133 }
134 
135 void drm_master_put(struct drm_master **master)
136 {
137 	kref_put(&(*master)->refcount, drm_master_destroy);
138 	*master = NULL;
139 }
140 EXPORT_SYMBOL(drm_master_put);
141 
142 int drm_setmaster_ioctl(struct drm_device *dev, void *data,
143 			struct drm_file *file_priv)
144 {
145 	int ret = 0;
146 
147 	mutex_lock(&dev->master_mutex);
148 	if (file_priv->is_master)
149 		goto out_unlock;
150 
151 	if (file_priv->minor->master) {
152 		ret = -EINVAL;
153 		goto out_unlock;
154 	}
155 
156 	if (!file_priv->master) {
157 		ret = -EINVAL;
158 		goto out_unlock;
159 	}
160 
161 	if (!file_priv->allowed_master) {
162 		ret = drm_new_set_master(dev, file_priv);
163 		goto out_unlock;
164 	}
165 
166 	file_priv->minor->master = drm_master_get(file_priv->master);
167 	file_priv->is_master = 1;
168 	if (dev->driver->master_set) {
169 		ret = dev->driver->master_set(dev, file_priv, false);
170 		if (unlikely(ret != 0)) {
171 			file_priv->is_master = 0;
172 			drm_master_put(&file_priv->minor->master);
173 		}
174 	}
175 
176 out_unlock:
177 	mutex_unlock(&dev->master_mutex);
178 	return ret;
179 }
180 
181 int drm_dropmaster_ioctl(struct drm_device *dev, void *data,
182 			 struct drm_file *file_priv)
183 {
184 	int ret = -EINVAL;
185 
186 	mutex_lock(&dev->master_mutex);
187 	if (!file_priv->is_master)
188 		goto out_unlock;
189 
190 	if (!file_priv->minor->master)
191 		goto out_unlock;
192 
193 	ret = 0;
194 	if (dev->driver->master_drop)
195 		dev->driver->master_drop(dev, file_priv, false);
196 	drm_master_put(&file_priv->minor->master);
197 	file_priv->is_master = 0;
198 
199 out_unlock:
200 	mutex_unlock(&dev->master_mutex);
201 	return ret;
202 }
203 
204 /*
205  * DRM Minors
206  * A DRM device can provide several char-dev interfaces on the DRM-Major. Each
207  * of them is represented by a drm_minor object. Depending on the capabilities
208  * of the device-driver, different interfaces are registered.
209  *
210  * Minors can be accessed via dev->$minor_name. This pointer is either
211  * NULL or a valid drm_minor pointer and stays valid as long as the device is
212  * valid. This means, DRM minors have the same life-time as the underlying
213  * device. However, this doesn't mean that the minor is active. Minors are
214  * registered and unregistered dynamically according to device-state.
215  */
216 
217 static struct drm_minor **drm_minor_get_slot(struct drm_device *dev,
218 					     unsigned int type)
219 {
220 	switch (type) {
221 	case DRM_MINOR_LEGACY:
222 		return &dev->primary;
223 	case DRM_MINOR_RENDER:
224 		return &dev->render;
225 	case DRM_MINOR_CONTROL:
226 		return &dev->control;
227 	default:
228 		return NULL;
229 	}
230 }
231 
232 static int drm_minor_alloc(struct drm_device *dev, unsigned int type)
233 {
234 	struct drm_minor *minor;
235 	unsigned long flags;
236 	int r;
237 
238 	minor = kzalloc(sizeof(*minor), GFP_KERNEL);
239 	if (!minor)
240 		return -ENOMEM;
241 
242 	minor->type = type;
243 	minor->dev = dev;
244 
245 	idr_preload(GFP_KERNEL);
246 	spin_lock_irqsave(&drm_minor_lock, flags);
247 	r = idr_alloc(&drm_minors_idr,
248 		      NULL,
249 		      64 * type,
250 		      64 * (type + 1),
251 		      GFP_NOWAIT);
252 	spin_unlock_irqrestore(&drm_minor_lock, flags);
253 	idr_preload_end();
254 
255 	if (r < 0)
256 		goto err_free;
257 
258 	minor->index = r;
259 
260 	minor->kdev = drm_sysfs_minor_alloc(minor);
261 	if (IS_ERR(minor->kdev)) {
262 		r = PTR_ERR(minor->kdev);
263 		goto err_index;
264 	}
265 
266 	*drm_minor_get_slot(dev, type) = minor;
267 	return 0;
268 
269 err_index:
270 	spin_lock_irqsave(&drm_minor_lock, flags);
271 	idr_remove(&drm_minors_idr, minor->index);
272 	spin_unlock_irqrestore(&drm_minor_lock, flags);
273 err_free:
274 	kfree(minor);
275 	return r;
276 }
277 
278 static void drm_minor_free(struct drm_device *dev, unsigned int type)
279 {
280 	struct drm_minor **slot, *minor;
281 	unsigned long flags;
282 
283 	slot = drm_minor_get_slot(dev, type);
284 	minor = *slot;
285 	if (!minor)
286 		return;
287 
288 	put_device(minor->kdev);
289 
290 	spin_lock_irqsave(&drm_minor_lock, flags);
291 	idr_remove(&drm_minors_idr, minor->index);
292 	spin_unlock_irqrestore(&drm_minor_lock, flags);
293 
294 	kfree(minor);
295 	*slot = NULL;
296 }
297 
298 static int drm_minor_register(struct drm_device *dev, unsigned int type)
299 {
300 	struct drm_minor *minor;
301 	unsigned long flags;
302 	int ret;
303 
304 	DRM_DEBUG("\n");
305 
306 	minor = *drm_minor_get_slot(dev, type);
307 	if (!minor)
308 		return 0;
309 
310 	ret = drm_debugfs_init(minor, minor->index, drm_debugfs_root);
311 	if (ret) {
312 		DRM_ERROR("DRM: Failed to initialize /sys/kernel/debug/dri.\n");
313 		return ret;
314 	}
315 
316 	ret = device_add(minor->kdev);
317 	if (ret)
318 		goto err_debugfs;
319 
320 	/* replace NULL with @minor so lookups will succeed from now on */
321 	spin_lock_irqsave(&drm_minor_lock, flags);
322 	idr_replace(&drm_minors_idr, minor, minor->index);
323 	spin_unlock_irqrestore(&drm_minor_lock, flags);
324 
325 	DRM_DEBUG("new minor registered %d\n", minor->index);
326 	return 0;
327 
328 err_debugfs:
329 	drm_debugfs_cleanup(minor);
330 	return ret;
331 }
332 
333 static void drm_minor_unregister(struct drm_device *dev, unsigned int type)
334 {
335 	struct drm_minor *minor;
336 	unsigned long flags;
337 
338 	minor = *drm_minor_get_slot(dev, type);
339 	if (!minor || !device_is_registered(minor->kdev))
340 		return;
341 
342 	/* replace @minor with NULL so lookups will fail from now on */
343 	spin_lock_irqsave(&drm_minor_lock, flags);
344 	idr_replace(&drm_minors_idr, NULL, minor->index);
345 	spin_unlock_irqrestore(&drm_minor_lock, flags);
346 
347 	device_del(minor->kdev);
348 	dev_set_drvdata(minor->kdev, NULL); /* safety belt */
349 	drm_debugfs_cleanup(minor);
350 }
351 
352 /**
353  * drm_minor_acquire - Acquire a DRM minor
354  * @minor_id: Minor ID of the DRM-minor
355  *
356  * Looks up the given minor-ID and returns the respective DRM-minor object. The
357  * refence-count of the underlying device is increased so you must release this
358  * object with drm_minor_release().
359  *
360  * As long as you hold this minor, it is guaranteed that the object and the
361  * minor->dev pointer will stay valid! However, the device may get unplugged and
362  * unregistered while you hold the minor.
363  *
364  * Returns:
365  * Pointer to minor-object with increased device-refcount, or PTR_ERR on
366  * failure.
367  */
368 struct drm_minor *drm_minor_acquire(unsigned int minor_id)
369 {
370 	struct drm_minor *minor;
371 	unsigned long flags;
372 
373 	spin_lock_irqsave(&drm_minor_lock, flags);
374 	minor = idr_find(&drm_minors_idr, minor_id);
375 	if (minor)
376 		drm_dev_ref(minor->dev);
377 	spin_unlock_irqrestore(&drm_minor_lock, flags);
378 
379 	if (!minor) {
380 		return ERR_PTR(-ENODEV);
381 	} else if (drm_device_is_unplugged(minor->dev)) {
382 		drm_dev_unref(minor->dev);
383 		return ERR_PTR(-ENODEV);
384 	}
385 
386 	return minor;
387 }
388 
389 /**
390  * drm_minor_release - Release DRM minor
391  * @minor: Pointer to DRM minor object
392  *
393  * Release a minor that was previously acquired via drm_minor_acquire().
394  */
395 void drm_minor_release(struct drm_minor *minor)
396 {
397 	drm_dev_unref(minor->dev);
398 }
399 
400 /**
401  * DOC: driver instance overview
402  *
403  * A device instance for a drm driver is represented by struct &drm_device. This
404  * is allocated with drm_dev_alloc(), usually from bus-specific ->probe()
405  * callbacks implemented by the driver. The driver then needs to initialize all
406  * the various subsystems for the drm device like memory management, vblank
407  * handling, modesetting support and intial output configuration plus obviously
408  * initialize all the corresponding hardware bits. An important part of this is
409  * also calling drm_dev_set_unique() to set the userspace-visible unique name of
410  * this device instance. Finally when everything is up and running and ready for
411  * userspace the device instance can be published using drm_dev_register().
412  *
413  * There is also deprecated support for initalizing device instances using
414  * bus-specific helpers and the ->load() callback. But due to
415  * backwards-compatibility needs the device instance have to be published too
416  * early, which requires unpretty global locking to make safe and is therefore
417  * only support for existing drivers not yet converted to the new scheme.
418  *
419  * When cleaning up a device instance everything needs to be done in reverse:
420  * First unpublish the device instance with drm_dev_unregister(). Then clean up
421  * any other resources allocated at device initialization and drop the driver's
422  * reference to &drm_device using drm_dev_unref().
423  *
424  * Note that the lifetime rules for &drm_device instance has still a lot of
425  * historical baggage. Hence use the reference counting provided by
426  * drm_dev_ref() and drm_dev_unref() only carefully.
427  *
428  * Also note that embedding of &drm_device is currently not (yet) supported (but
429  * it would be easy to add). Drivers can store driver-private data in the
430  * dev_priv field of &drm_device.
431  */
432 
433 /**
434  * drm_put_dev - Unregister and release a DRM device
435  * @dev: DRM device
436  *
437  * Called at module unload time or when a PCI device is unplugged.
438  *
439  * Cleans up all DRM device, calling drm_lastclose().
440  *
441  * Note: Use of this function is deprecated. It will eventually go away
442  * completely.  Please use drm_dev_unregister() and drm_dev_unref() explicitly
443  * instead to make sure that the device isn't userspace accessible any more
444  * while teardown is in progress, ensuring that userspace can't access an
445  * inconsistent state.
446  */
447 void drm_put_dev(struct drm_device *dev)
448 {
449 	DRM_DEBUG("\n");
450 
451 	if (!dev) {
452 		DRM_ERROR("cleanup called no dev\n");
453 		return;
454 	}
455 
456 	drm_dev_unregister(dev);
457 	drm_dev_unref(dev);
458 }
459 EXPORT_SYMBOL(drm_put_dev);
460 
461 void drm_unplug_dev(struct drm_device *dev)
462 {
463 	/* for a USB device */
464 	drm_minor_unregister(dev, DRM_MINOR_LEGACY);
465 	drm_minor_unregister(dev, DRM_MINOR_RENDER);
466 	drm_minor_unregister(dev, DRM_MINOR_CONTROL);
467 
468 	mutex_lock(&drm_global_mutex);
469 
470 	drm_device_set_unplugged(dev);
471 
472 	if (dev->open_count == 0) {
473 		drm_put_dev(dev);
474 	}
475 	mutex_unlock(&drm_global_mutex);
476 }
477 EXPORT_SYMBOL(drm_unplug_dev);
478 
479 /*
480  * DRM internal mount
481  * We want to be able to allocate our own "struct address_space" to control
482  * memory-mappings in VRAM (or stolen RAM, ...). However, core MM does not allow
483  * stand-alone address_space objects, so we need an underlying inode. As there
484  * is no way to allocate an independent inode easily, we need a fake internal
485  * VFS mount-point.
486  *
487  * The drm_fs_inode_new() function allocates a new inode, drm_fs_inode_free()
488  * frees it again. You are allowed to use iget() and iput() to get references to
489  * the inode. But each drm_fs_inode_new() call must be paired with exactly one
490  * drm_fs_inode_free() call (which does not have to be the last iput()).
491  * We use drm_fs_inode_*() to manage our internal VFS mount-point and share it
492  * between multiple inode-users. You could, technically, call
493  * iget() + drm_fs_inode_free() directly after alloc and sometime later do an
494  * iput(), but this way you'd end up with a new vfsmount for each inode.
495  */
496 
497 static int drm_fs_cnt;
498 static struct vfsmount *drm_fs_mnt;
499 
500 static const struct dentry_operations drm_fs_dops = {
501 	.d_dname	= simple_dname,
502 };
503 
504 static const struct super_operations drm_fs_sops = {
505 	.statfs		= simple_statfs,
506 };
507 
508 static struct dentry *drm_fs_mount(struct file_system_type *fs_type, int flags,
509 				   const char *dev_name, void *data)
510 {
511 	return mount_pseudo(fs_type,
512 			    "drm:",
513 			    &drm_fs_sops,
514 			    &drm_fs_dops,
515 			    0x010203ff);
516 }
517 
518 static struct file_system_type drm_fs_type = {
519 	.name		= "drm",
520 	.owner		= THIS_MODULE,
521 	.mount		= drm_fs_mount,
522 	.kill_sb	= kill_anon_super,
523 };
524 
525 static struct inode *drm_fs_inode_new(void)
526 {
527 	struct inode *inode;
528 	int r;
529 
530 	r = simple_pin_fs(&drm_fs_type, &drm_fs_mnt, &drm_fs_cnt);
531 	if (r < 0) {
532 		DRM_ERROR("Cannot mount pseudo fs: %d\n", r);
533 		return ERR_PTR(r);
534 	}
535 
536 	inode = alloc_anon_inode(drm_fs_mnt->mnt_sb);
537 	if (IS_ERR(inode))
538 		simple_release_fs(&drm_fs_mnt, &drm_fs_cnt);
539 
540 	return inode;
541 }
542 
543 static void drm_fs_inode_free(struct inode *inode)
544 {
545 	if (inode) {
546 		iput(inode);
547 		simple_release_fs(&drm_fs_mnt, &drm_fs_cnt);
548 	}
549 }
550 
551 /**
552  * drm_dev_alloc - Allocate new DRM device
553  * @driver: DRM driver to allocate device for
554  * @parent: Parent device object
555  *
556  * Allocate and initialize a new DRM device. No device registration is done.
557  * Call drm_dev_register() to advertice the device to user space and register it
558  * with other core subsystems. This should be done last in the device
559  * initialization sequence to make sure userspace can't access an inconsistent
560  * state.
561  *
562  * The initial ref-count of the object is 1. Use drm_dev_ref() and
563  * drm_dev_unref() to take and drop further ref-counts.
564  *
565  * Note that for purely virtual devices @parent can be NULL.
566  *
567  * RETURNS:
568  * Pointer to new DRM device, or NULL if out of memory.
569  */
570 struct drm_device *drm_dev_alloc(struct drm_driver *driver,
571 				 struct device *parent)
572 {
573 	struct drm_device *dev;
574 	int ret;
575 
576 	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
577 	if (!dev)
578 		return NULL;
579 
580 	kref_init(&dev->ref);
581 	dev->dev = parent;
582 	dev->driver = driver;
583 
584 	INIT_LIST_HEAD(&dev->filelist);
585 	INIT_LIST_HEAD(&dev->ctxlist);
586 	INIT_LIST_HEAD(&dev->vmalist);
587 	INIT_LIST_HEAD(&dev->maplist);
588 	INIT_LIST_HEAD(&dev->vblank_event_list);
589 
590 	spin_lock_init(&dev->buf_lock);
591 	spin_lock_init(&dev->event_lock);
592 	mutex_init(&dev->struct_mutex);
593 	mutex_init(&dev->filelist_mutex);
594 	mutex_init(&dev->ctxlist_mutex);
595 	mutex_init(&dev->master_mutex);
596 
597 	dev->anon_inode = drm_fs_inode_new();
598 	if (IS_ERR(dev->anon_inode)) {
599 		ret = PTR_ERR(dev->anon_inode);
600 		DRM_ERROR("Cannot allocate anonymous inode: %d\n", ret);
601 		goto err_free;
602 	}
603 
604 	if (drm_core_check_feature(dev, DRIVER_MODESET)) {
605 		ret = drm_minor_alloc(dev, DRM_MINOR_CONTROL);
606 		if (ret)
607 			goto err_minors;
608 
609 		WARN_ON(driver->suspend || driver->resume);
610 	}
611 
612 	if (drm_core_check_feature(dev, DRIVER_RENDER)) {
613 		ret = drm_minor_alloc(dev, DRM_MINOR_RENDER);
614 		if (ret)
615 			goto err_minors;
616 	}
617 
618 	ret = drm_minor_alloc(dev, DRM_MINOR_LEGACY);
619 	if (ret)
620 		goto err_minors;
621 
622 	if (drm_ht_create(&dev->map_hash, 12))
623 		goto err_minors;
624 
625 	drm_legacy_ctxbitmap_init(dev);
626 
627 	if (drm_core_check_feature(dev, DRIVER_GEM)) {
628 		ret = drm_gem_init(dev);
629 		if (ret) {
630 			DRM_ERROR("Cannot initialize graphics execution manager (GEM)\n");
631 			goto err_ctxbitmap;
632 		}
633 	}
634 
635 	if (parent) {
636 		ret = drm_dev_set_unique(dev, dev_name(parent));
637 		if (ret)
638 			goto err_setunique;
639 	}
640 
641 	return dev;
642 
643 err_setunique:
644 	if (drm_core_check_feature(dev, DRIVER_GEM))
645 		drm_gem_destroy(dev);
646 err_ctxbitmap:
647 	drm_legacy_ctxbitmap_cleanup(dev);
648 	drm_ht_remove(&dev->map_hash);
649 err_minors:
650 	drm_minor_free(dev, DRM_MINOR_LEGACY);
651 	drm_minor_free(dev, DRM_MINOR_RENDER);
652 	drm_minor_free(dev, DRM_MINOR_CONTROL);
653 	drm_fs_inode_free(dev->anon_inode);
654 err_free:
655 	mutex_destroy(&dev->master_mutex);
656 	kfree(dev);
657 	return NULL;
658 }
659 EXPORT_SYMBOL(drm_dev_alloc);
660 
661 static void drm_dev_release(struct kref *ref)
662 {
663 	struct drm_device *dev = container_of(ref, struct drm_device, ref);
664 
665 	if (drm_core_check_feature(dev, DRIVER_GEM))
666 		drm_gem_destroy(dev);
667 
668 	drm_legacy_ctxbitmap_cleanup(dev);
669 	drm_ht_remove(&dev->map_hash);
670 	drm_fs_inode_free(dev->anon_inode);
671 
672 	drm_minor_free(dev, DRM_MINOR_LEGACY);
673 	drm_minor_free(dev, DRM_MINOR_RENDER);
674 	drm_minor_free(dev, DRM_MINOR_CONTROL);
675 
676 	mutex_destroy(&dev->master_mutex);
677 	kfree(dev->unique);
678 	kfree(dev);
679 }
680 
681 /**
682  * drm_dev_ref - Take reference of a DRM device
683  * @dev: device to take reference of or NULL
684  *
685  * This increases the ref-count of @dev by one. You *must* already own a
686  * reference when calling this. Use drm_dev_unref() to drop this reference
687  * again.
688  *
689  * This function never fails. However, this function does not provide *any*
690  * guarantee whether the device is alive or running. It only provides a
691  * reference to the object and the memory associated with it.
692  */
693 void drm_dev_ref(struct drm_device *dev)
694 {
695 	if (dev)
696 		kref_get(&dev->ref);
697 }
698 EXPORT_SYMBOL(drm_dev_ref);
699 
700 /**
701  * drm_dev_unref - Drop reference of a DRM device
702  * @dev: device to drop reference of or NULL
703  *
704  * This decreases the ref-count of @dev by one. The device is destroyed if the
705  * ref-count drops to zero.
706  */
707 void drm_dev_unref(struct drm_device *dev)
708 {
709 	if (dev)
710 		kref_put(&dev->ref, drm_dev_release);
711 }
712 EXPORT_SYMBOL(drm_dev_unref);
713 
714 /**
715  * drm_dev_register - Register DRM device
716  * @dev: Device to register
717  * @flags: Flags passed to the driver's .load() function
718  *
719  * Register the DRM device @dev with the system, advertise device to user-space
720  * and start normal device operation. @dev must be allocated via drm_dev_alloc()
721  * previously. Right after drm_dev_register() the driver should call
722  * drm_connector_register_all() to register all connectors in sysfs. This is
723  * a separate call for backward compatibility with drivers still using
724  * the deprecated ->load() callback, where connectors are registered from within
725  * the ->load() callback.
726  *
727  * Never call this twice on any device!
728  *
729  * NOTE: To ensure backward compatibility with existing drivers method this
730  * function calls the ->load() method after registering the device nodes,
731  * creating race conditions. Usage of the ->load() methods is therefore
732  * deprecated, drivers must perform all initialization before calling
733  * drm_dev_register().
734  *
735  * RETURNS:
736  * 0 on success, negative error code on failure.
737  */
738 int drm_dev_register(struct drm_device *dev, unsigned long flags)
739 {
740 	int ret;
741 
742 	mutex_lock(&drm_global_mutex);
743 
744 	ret = drm_minor_register(dev, DRM_MINOR_CONTROL);
745 	if (ret)
746 		goto err_minors;
747 
748 	ret = drm_minor_register(dev, DRM_MINOR_RENDER);
749 	if (ret)
750 		goto err_minors;
751 
752 	ret = drm_minor_register(dev, DRM_MINOR_LEGACY);
753 	if (ret)
754 		goto err_minors;
755 
756 	if (dev->driver->load) {
757 		ret = dev->driver->load(dev, flags);
758 		if (ret)
759 			goto err_minors;
760 	}
761 
762 	ret = 0;
763 	goto out_unlock;
764 
765 err_minors:
766 	drm_minor_unregister(dev, DRM_MINOR_LEGACY);
767 	drm_minor_unregister(dev, DRM_MINOR_RENDER);
768 	drm_minor_unregister(dev, DRM_MINOR_CONTROL);
769 out_unlock:
770 	mutex_unlock(&drm_global_mutex);
771 	return ret;
772 }
773 EXPORT_SYMBOL(drm_dev_register);
774 
775 /**
776  * drm_dev_unregister - Unregister DRM device
777  * @dev: Device to unregister
778  *
779  * Unregister the DRM device from the system. This does the reverse of
780  * drm_dev_register() but does not deallocate the device. The caller must call
781  * drm_dev_unref() to drop their final reference.
782  *
783  * This should be called first in the device teardown code to make sure
784  * userspace can't access the device instance any more.
785  */
786 void drm_dev_unregister(struct drm_device *dev)
787 {
788 	struct drm_map_list *r_list, *list_temp;
789 
790 	drm_lastclose(dev);
791 
792 	if (dev->driver->unload)
793 		dev->driver->unload(dev);
794 
795 	if (dev->agp)
796 		drm_pci_agp_destroy(dev);
797 
798 	drm_vblank_cleanup(dev);
799 
800 	list_for_each_entry_safe(r_list, list_temp, &dev->maplist, head)
801 		drm_legacy_rmmap(dev, r_list->map);
802 
803 	drm_minor_unregister(dev, DRM_MINOR_LEGACY);
804 	drm_minor_unregister(dev, DRM_MINOR_RENDER);
805 	drm_minor_unregister(dev, DRM_MINOR_CONTROL);
806 }
807 EXPORT_SYMBOL(drm_dev_unregister);
808 
809 /**
810  * drm_dev_set_unique - Set the unique name of a DRM device
811  * @dev: device of which to set the unique name
812  * @name: unique name
813  *
814  * Sets the unique name of a DRM device using the specified string. Drivers
815  * can use this at driver probe time if the unique name of the devices they
816  * drive is static.
817  *
818  * Return: 0 on success or a negative error code on failure.
819  */
820 int drm_dev_set_unique(struct drm_device *dev, const char *name)
821 {
822 	kfree(dev->unique);
823 	dev->unique = kstrdup(name, GFP_KERNEL);
824 
825 	return dev->unique ? 0 : -ENOMEM;
826 }
827 EXPORT_SYMBOL(drm_dev_set_unique);
828 
829 /*
830  * DRM Core
831  * The DRM core module initializes all global DRM objects and makes them
832  * available to drivers. Once setup, drivers can probe their respective
833  * devices.
834  * Currently, core management includes:
835  *  - The "DRM-Global" key/value database
836  *  - Global ID management for connectors
837  *  - DRM major number allocation
838  *  - DRM minor management
839  *  - DRM sysfs class
840  *  - DRM debugfs root
841  *
842  * Furthermore, the DRM core provides dynamic char-dev lookups. For each
843  * interface registered on a DRM device, you can request minor numbers from DRM
844  * core. DRM core takes care of major-number management and char-dev
845  * registration. A stub ->open() callback forwards any open() requests to the
846  * registered minor.
847  */
848 
849 static int drm_stub_open(struct inode *inode, struct file *filp)
850 {
851 	const struct file_operations *new_fops;
852 	struct drm_minor *minor;
853 	int err;
854 
855 	DRM_DEBUG("\n");
856 
857 	mutex_lock(&drm_global_mutex);
858 	minor = drm_minor_acquire(iminor(inode));
859 	if (IS_ERR(minor)) {
860 		err = PTR_ERR(minor);
861 		goto out_unlock;
862 	}
863 
864 	new_fops = fops_get(minor->dev->driver->fops);
865 	if (!new_fops) {
866 		err = -ENODEV;
867 		goto out_release;
868 	}
869 
870 	replace_fops(filp, new_fops);
871 	if (filp->f_op->open)
872 		err = filp->f_op->open(inode, filp);
873 	else
874 		err = 0;
875 
876 out_release:
877 	drm_minor_release(minor);
878 out_unlock:
879 	mutex_unlock(&drm_global_mutex);
880 	return err;
881 }
882 
883 static const struct file_operations drm_stub_fops = {
884 	.owner = THIS_MODULE,
885 	.open = drm_stub_open,
886 	.llseek = noop_llseek,
887 };
888 
889 static int __init drm_core_init(void)
890 {
891 	int ret = -ENOMEM;
892 
893 	drm_global_init();
894 	drm_connector_ida_init();
895 	idr_init(&drm_minors_idr);
896 
897 	if (register_chrdev(DRM_MAJOR, "drm", &drm_stub_fops))
898 		goto err_p1;
899 
900 	ret = drm_sysfs_init();
901 	if (ret < 0) {
902 		printk(KERN_ERR "DRM: Error creating drm class.\n");
903 		goto err_p2;
904 	}
905 
906 	drm_debugfs_root = debugfs_create_dir("dri", NULL);
907 	if (!drm_debugfs_root) {
908 		DRM_ERROR("Cannot create /sys/kernel/debug/dri\n");
909 		ret = -1;
910 		goto err_p3;
911 	}
912 
913 	DRM_INFO("Initialized %s %d.%d.%d %s\n",
914 		 CORE_NAME, CORE_MAJOR, CORE_MINOR, CORE_PATCHLEVEL, CORE_DATE);
915 	return 0;
916 err_p3:
917 	drm_sysfs_destroy();
918 err_p2:
919 	unregister_chrdev(DRM_MAJOR, "drm");
920 
921 	idr_destroy(&drm_minors_idr);
922 err_p1:
923 	return ret;
924 }
925 
926 static void __exit drm_core_exit(void)
927 {
928 	debugfs_remove(drm_debugfs_root);
929 	drm_sysfs_destroy();
930 
931 	unregister_chrdev(DRM_MAJOR, "drm");
932 
933 	drm_connector_ida_destroy();
934 	idr_destroy(&drm_minors_idr);
935 }
936 
937 module_init(drm_core_init);
938 module_exit(drm_core_exit);
939