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
 36#include <drm/drm_drv.h>
 37#include <drm/drmP.h>
 
 38
 39#include "drm_crtc_internal.h"
 40#include "drm_legacy.h"
 41#include "drm_internal.h"
 42#include "drm_crtc_internal.h"
 43
 44/*
 45 * drm_debug: Enable debug output.
 46 * Bitmask of DRM_UT_x. See include/drm/drmP.h for details.
 47 */
 48unsigned int drm_debug = 0;
 49EXPORT_SYMBOL(drm_debug);
 50
 51MODULE_AUTHOR("Gareth Hughes, Leif Delgass, José Fonseca, Jon Smirl");
 52MODULE_DESCRIPTION("DRM shared core routines");
 53MODULE_LICENSE("GPL and additional rights");
 54MODULE_PARM_DESC(debug, "Enable debug output, where each bit enables a debug category.\n"
 55"\t\tBit 0 (0x01) will enable CORE messages (drm core code)\n"
 56"\t\tBit 1 (0x02) will enable DRIVER messages (drm controller code)\n"
 57"\t\tBit 2 (0x04) will enable KMS messages (modesetting code)\n"
 58"\t\tBit 3 (0x08) will enable PRIME messages (prime code)\n"
 59"\t\tBit 4 (0x10) will enable ATOMIC messages (atomic code)\n"
 60"\t\tBit 5 (0x20) will enable VBL messages (vblank code)\n"
 61"\t\tBit 7 (0x80) will enable LEASE messages (leasing code)");
 62module_param_named(debug, drm_debug, int, 0600);
 63
 64static DEFINE_SPINLOCK(drm_minor_lock);
 65static struct idr drm_minors_idr;
 66
 67/*
 68 * If the drm core fails to init for whatever reason,
 69 * we should prevent any drivers from registering with it.
 70 * It's best to check this at drm_dev_init(), as some drivers
 71 * prefer to embed struct drm_device into their own device
 72 * structure and call drm_dev_init() themselves.
 73 */
 74static bool drm_core_init_complete = false;
 75
 76static struct dentry *drm_debugfs_root;
 77
 78/*
 79 * DRM Minors
 80 * A DRM device can provide several char-dev interfaces on the DRM-Major. Each
 81 * of them is represented by a drm_minor object. Depending on the capabilities
 82 * of the device-driver, different interfaces are registered.
 83 *
 84 * Minors can be accessed via dev->$minor_name. This pointer is either
 85 * NULL or a valid drm_minor pointer and stays valid as long as the device is
 86 * valid. This means, DRM minors have the same life-time as the underlying
 87 * device. However, this doesn't mean that the minor is active. Minors are
 88 * registered and unregistered dynamically according to device-state.
 89 */
 90
 91static struct drm_minor **drm_minor_get_slot(struct drm_device *dev,
 92					     unsigned int type)
 93{
 94	switch (type) {
 95	case DRM_MINOR_PRIMARY:
 96		return &dev->primary;
 97	case DRM_MINOR_RENDER:
 98		return &dev->render;
 99	case DRM_MINOR_CONTROL:
100		return &dev->control;
101	default:
102		BUG();
103	}
104}
105
106static int drm_minor_alloc(struct drm_device *dev, unsigned int type)
107{
108	struct drm_minor *minor;
109	unsigned long flags;
110	int r;
111
112	minor = kzalloc(sizeof(*minor), GFP_KERNEL);
113	if (!minor)
114		return -ENOMEM;
115
116	minor->type = type;
117	minor->dev = dev;
118
119	idr_preload(GFP_KERNEL);
120	spin_lock_irqsave(&drm_minor_lock, flags);
121	r = idr_alloc(&drm_minors_idr,
122		      NULL,
123		      64 * type,
124		      64 * (type + 1),
125		      GFP_NOWAIT);
126	spin_unlock_irqrestore(&drm_minor_lock, flags);
127	idr_preload_end();
128
129	if (r < 0)
130		goto err_free;
131
132	minor->index = r;
133
134	minor->kdev = drm_sysfs_minor_alloc(minor);
135	if (IS_ERR(minor->kdev)) {
136		r = PTR_ERR(minor->kdev);
137		goto err_index;
138	}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
139
140	*drm_minor_get_slot(dev, type) = minor;
141	return 0;
142
143err_index:
144	spin_lock_irqsave(&drm_minor_lock, flags);
145	idr_remove(&drm_minors_idr, minor->index);
146	spin_unlock_irqrestore(&drm_minor_lock, flags);
147err_free:
148	kfree(minor);
149	return r;
150}
151
152static void drm_minor_free(struct drm_device *dev, unsigned int type)
153{
154	struct drm_minor **slot, *minor;
155	unsigned long flags;
156
157	slot = drm_minor_get_slot(dev, type);
158	minor = *slot;
159	if (!minor)
160		return;
161
162	put_device(minor->kdev);
163
164	spin_lock_irqsave(&drm_minor_lock, flags);
165	idr_remove(&drm_minors_idr, minor->index);
166	spin_unlock_irqrestore(&drm_minor_lock, flags);
167
168	kfree(minor);
169	*slot = NULL;
170}
171
172static int drm_minor_register(struct drm_device *dev, unsigned int type)
173{
174	struct drm_minor *minor;
175	unsigned long flags;
176	int ret;
177
178	DRM_DEBUG("\n");
179
180	minor = *drm_minor_get_slot(dev, type);
181	if (!minor)
182		return 0;
183
184	ret = drm_debugfs_init(minor, minor->index, drm_debugfs_root);
185	if (ret) {
186		DRM_ERROR("DRM: Failed to initialize /sys/kernel/debug/dri.\n");
187		goto err_debugfs;
188	}
189
190	ret = device_add(minor->kdev);
191	if (ret)
192		goto err_debugfs;
193
194	/* replace NULL with @minor so lookups will succeed from now on */
195	spin_lock_irqsave(&drm_minor_lock, flags);
196	idr_replace(&drm_minors_idr, minor, minor->index);
197	spin_unlock_irqrestore(&drm_minor_lock, flags);
198
199	DRM_DEBUG("new minor registered %d\n", minor->index);
 
200	return 0;
 
 
 
 
201
202err_debugfs:
203	drm_debugfs_cleanup(minor);
204	return ret;
205}
206
207static void drm_minor_unregister(struct drm_device *dev, unsigned int type)
208{
209	struct drm_minor *minor;
210	unsigned long flags;
211
212	minor = *drm_minor_get_slot(dev, type);
213	if (!minor || !device_is_registered(minor->kdev))
214		return;
215
216	/* replace @minor with NULL so lookups will fail from now on */
217	spin_lock_irqsave(&drm_minor_lock, flags);
218	idr_replace(&drm_minors_idr, NULL, minor->index);
219	spin_unlock_irqrestore(&drm_minor_lock, flags);
220
221	device_del(minor->kdev);
222	dev_set_drvdata(minor->kdev, NULL); /* safety belt */
223	drm_debugfs_cleanup(minor);
224}
225
226/*
227 * Looks up the given minor-ID and returns the respective DRM-minor object. The
228 * refence-count of the underlying device is increased so you must release this
229 * object with drm_minor_release().
230 *
231 * As long as you hold this minor, it is guaranteed that the object and the
232 * minor->dev pointer will stay valid! However, the device may get unplugged and
233 * unregistered while you hold the minor.
234 */
235struct drm_minor *drm_minor_acquire(unsigned int minor_id)
236{
237	struct drm_minor *minor;
238	unsigned long flags;
239
240	spin_lock_irqsave(&drm_minor_lock, flags);
241	minor = idr_find(&drm_minors_idr, minor_id);
242	if (minor)
243		drm_dev_get(minor->dev);
244	spin_unlock_irqrestore(&drm_minor_lock, flags);
245
246	if (!minor) {
247		return ERR_PTR(-ENODEV);
248	} else if (drm_dev_is_unplugged(minor->dev)) {
249		drm_dev_put(minor->dev);
250		return ERR_PTR(-ENODEV);
251	}
252
253	return minor;
254}
255
256void drm_minor_release(struct drm_minor *minor)
257{
258	drm_dev_put(minor->dev);
259}
260
261/**
262 * DOC: driver instance overview
263 *
264 * A device instance for a drm driver is represented by &struct drm_device. This
265 * is allocated with drm_dev_alloc(), usually from bus-specific ->probe()
266 * callbacks implemented by the driver. The driver then needs to initialize all
267 * the various subsystems for the drm device like memory management, vblank
268 * handling, modesetting support and intial output configuration plus obviously
269 * initialize all the corresponding hardware bits. An important part of this is
270 * also calling drm_dev_set_unique() to set the userspace-visible unique name of
271 * this device instance. Finally when everything is up and running and ready for
272 * userspace the device instance can be published using drm_dev_register().
273 *
274 * There is also deprecated support for initalizing device instances using
275 * bus-specific helpers and the &drm_driver.load callback. But due to
276 * backwards-compatibility needs the device instance have to be published too
277 * early, which requires unpretty global locking to make safe and is therefore
278 * only support for existing drivers not yet converted to the new scheme.
279 *
280 * When cleaning up a device instance everything needs to be done in reverse:
281 * First unpublish the device instance with drm_dev_unregister(). Then clean up
282 * any other resources allocated at device initialization and drop the driver's
283 * reference to &drm_device using drm_dev_put().
284 *
285 * Note that the lifetime rules for &drm_device instance has still a lot of
286 * historical baggage. Hence use the reference counting provided by
287 * drm_dev_get() and drm_dev_put() only carefully.
288 *
289 * It is recommended that drivers embed &struct drm_device into their own device
290 * structure, which is supported through drm_dev_init().
291 */
292
293/**
294 * drm_put_dev - Unregister and release a DRM device
295 * @dev: DRM device
296 *
297 * Called at module unload time or when a PCI device is unplugged.
298 *
299 * Cleans up all DRM device, calling drm_lastclose().
300 *
301 * Note: Use of this function is deprecated. It will eventually go away
302 * completely.  Please use drm_dev_unregister() and drm_dev_put() explicitly
303 * instead to make sure that the device isn't userspace accessible any more
304 * while teardown is in progress, ensuring that userspace can't access an
305 * inconsistent state.
306 */
307void drm_put_dev(struct drm_device *dev)
308{
309	DRM_DEBUG("\n");
310
311	if (!dev) {
312		DRM_ERROR("cleanup called no dev\n");
313		return;
314	}
315
316	drm_dev_unregister(dev);
317	drm_dev_put(dev);
318}
319EXPORT_SYMBOL(drm_put_dev);
320
321static void drm_device_set_unplugged(struct drm_device *dev)
322{
323	smp_wmb();
324	atomic_set(&dev->unplugged, 1);
 
325}
326
327/**
328 * drm_dev_unplug - unplug a DRM device
329 * @dev: DRM device
330 *
331 * This unplugs a hotpluggable DRM device, which makes it inaccessible to
332 * userspace operations. Entry-points can use drm_dev_is_unplugged(). This
333 * essentially unregisters the device like drm_dev_unregister(), but can be
334 * called while there are still open users of @dev.
335 */
336void drm_dev_unplug(struct drm_device *dev)
337{
338	drm_dev_unregister(dev);
339
340	mutex_lock(&drm_global_mutex);
341	drm_device_set_unplugged(dev);
342	if (dev->open_count == 0)
343		drm_dev_put(dev);
344	mutex_unlock(&drm_global_mutex);
345}
346EXPORT_SYMBOL(drm_dev_unplug);
347
348/*
349 * DRM internal mount
350 * We want to be able to allocate our own "struct address_space" to control
351 * memory-mappings in VRAM (or stolen RAM, ...). However, core MM does not allow
352 * stand-alone address_space objects, so we need an underlying inode. As there
353 * is no way to allocate an independent inode easily, we need a fake internal
354 * VFS mount-point.
355 *
356 * The drm_fs_inode_new() function allocates a new inode, drm_fs_inode_free()
357 * frees it again. You are allowed to use iget() and iput() to get references to
358 * the inode. But each drm_fs_inode_new() call must be paired with exactly one
359 * drm_fs_inode_free() call (which does not have to be the last iput()).
360 * We use drm_fs_inode_*() to manage our internal VFS mount-point and share it
361 * between multiple inode-users. You could, technically, call
362 * iget() + drm_fs_inode_free() directly after alloc and sometime later do an
363 * iput(), but this way you'd end up with a new vfsmount for each inode.
364 */
365
366static int drm_fs_cnt;
367static struct vfsmount *drm_fs_mnt;
368
369static const struct dentry_operations drm_fs_dops = {
370	.d_dname	= simple_dname,
371};
372
373static const struct super_operations drm_fs_sops = {
374	.statfs		= simple_statfs,
375};
376
377static struct dentry *drm_fs_mount(struct file_system_type *fs_type, int flags,
378				   const char *dev_name, void *data)
379{
380	return mount_pseudo(fs_type,
381			    "drm:",
382			    &drm_fs_sops,
383			    &drm_fs_dops,
384			    0x010203ff);
385}
386
387static struct file_system_type drm_fs_type = {
388	.name		= "drm",
389	.owner		= THIS_MODULE,
390	.mount		= drm_fs_mount,
391	.kill_sb	= kill_anon_super,
392};
393
394static struct inode *drm_fs_inode_new(void)
395{
396	struct inode *inode;
397	int r;
398
399	r = simple_pin_fs(&drm_fs_type, &drm_fs_mnt, &drm_fs_cnt);
400	if (r < 0) {
401		DRM_ERROR("Cannot mount pseudo fs: %d\n", r);
402		return ERR_PTR(r);
403	}
404
405	inode = alloc_anon_inode(drm_fs_mnt->mnt_sb);
406	if (IS_ERR(inode))
407		simple_release_fs(&drm_fs_mnt, &drm_fs_cnt);
408
409	return inode;
410}
411
412static void drm_fs_inode_free(struct inode *inode)
413{
414	if (inode) {
415		iput(inode);
416		simple_release_fs(&drm_fs_mnt, &drm_fs_cnt);
417	}
418}
419
420/**
421 * drm_dev_init - Initialise new DRM device
422 * @dev: DRM device
423 * @driver: DRM driver
424 * @parent: Parent device object
425 *
426 * Initialize a new DRM device. No device registration is done.
427 * Call drm_dev_register() to advertice the device to user space and register it
428 * with other core subsystems. This should be done last in the device
429 * initialization sequence to make sure userspace can't access an inconsistent
430 * state.
431 *
432 * The initial ref-count of the object is 1. Use drm_dev_get() and
433 * drm_dev_put() to take and drop further ref-counts.
434 *
435 * Note that for purely virtual devices @parent can be NULL.
436 *
437 * Drivers that do not want to allocate their own device struct
438 * embedding &struct drm_device can call drm_dev_alloc() instead. For drivers
439 * that do embed &struct drm_device it must be placed first in the overall
440 * structure, and the overall structure must be allocated using kmalloc(): The
441 * drm core's release function unconditionally calls kfree() on the @dev pointer
442 * when the final reference is released. To override this behaviour, and so
443 * allow embedding of the drm_device inside the driver's device struct at an
444 * arbitrary offset, you must supply a &drm_driver.release callback and control
445 * the finalization explicitly.
446 *
447 * RETURNS:
448 * 0 on success, or error code on failure.
449 */
450int drm_dev_init(struct drm_device *dev,
451		 struct drm_driver *driver,
452		 struct device *parent)
453{
454	int ret;
455
456	if (!drm_core_init_complete) {
457		DRM_ERROR("DRM core is not initialized\n");
458		return -ENODEV;
459	}
460
461	kref_init(&dev->ref);
462	dev->dev = parent;
463	dev->driver = driver;
464
465	INIT_LIST_HEAD(&dev->filelist);
466	INIT_LIST_HEAD(&dev->ctxlist);
467	INIT_LIST_HEAD(&dev->vmalist);
468	INIT_LIST_HEAD(&dev->maplist);
469	INIT_LIST_HEAD(&dev->vblank_event_list);
470
471	spin_lock_init(&dev->buf_lock);
472	spin_lock_init(&dev->event_lock);
473	mutex_init(&dev->struct_mutex);
474	mutex_init(&dev->filelist_mutex);
475	mutex_init(&dev->ctxlist_mutex);
476	mutex_init(&dev->master_mutex);
477
478	dev->anon_inode = drm_fs_inode_new();
479	if (IS_ERR(dev->anon_inode)) {
480		ret = PTR_ERR(dev->anon_inode);
481		DRM_ERROR("Cannot allocate anonymous inode: %d\n", ret);
482		goto err_free;
483	}
484
485	if (drm_core_check_feature(dev, DRIVER_RENDER)) {
486		ret = drm_minor_alloc(dev, DRM_MINOR_RENDER);
487		if (ret)
488			goto err_minors;
489	}
490
491	ret = drm_minor_alloc(dev, DRM_MINOR_PRIMARY);
492	if (ret)
493		goto err_minors;
494
495	ret = drm_ht_create(&dev->map_hash, 12);
496	if (ret)
497		goto err_minors;
498
499	drm_legacy_ctxbitmap_init(dev);
500
501	if (drm_core_check_feature(dev, DRIVER_GEM)) {
502		ret = drm_gem_init(dev);
503		if (ret) {
504			DRM_ERROR("Cannot initialize graphics execution manager (GEM)\n");
505			goto err_ctxbitmap;
506		}
507	}
508
509	/* Use the parent device name as DRM device unique identifier, but fall
510	 * back to the driver name for virtual devices like vgem. */
511	ret = drm_dev_set_unique(dev, parent ? dev_name(parent) : driver->name);
512	if (ret)
513		goto err_setunique;
514
515	return 0;
 
 
 
 
 
 
 
 
 
 
516
517err_setunique:
518	if (drm_core_check_feature(dev, DRIVER_GEM))
519		drm_gem_destroy(dev);
520err_ctxbitmap:
521	drm_legacy_ctxbitmap_cleanup(dev);
522	drm_ht_remove(&dev->map_hash);
523err_minors:
524	drm_minor_free(dev, DRM_MINOR_PRIMARY);
525	drm_minor_free(dev, DRM_MINOR_RENDER);
526	drm_minor_free(dev, DRM_MINOR_CONTROL);
527	drm_fs_inode_free(dev->anon_inode);
528err_free:
529	mutex_destroy(&dev->master_mutex);
530	mutex_destroy(&dev->ctxlist_mutex);
531	mutex_destroy(&dev->filelist_mutex);
532	mutex_destroy(&dev->struct_mutex);
533	return ret;
534}
535EXPORT_SYMBOL(drm_dev_init);
536
537/**
538 * drm_dev_fini - Finalize a dead DRM device
539 * @dev: DRM device
540 *
541 * Finalize a dead DRM device. This is the converse to drm_dev_init() and
542 * frees up all data allocated by it. All driver private data should be
543 * finalized first. Note that this function does not free the @dev, that is
544 * left to the caller.
545 *
546 * The ref-count of @dev must be zero, and drm_dev_fini() should only be called
547 * from a &drm_driver.release callback.
548 */
549void drm_dev_fini(struct drm_device *dev)
550{
551	drm_vblank_cleanup(dev);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
552
553	if (drm_core_check_feature(dev, DRIVER_GEM))
554		drm_gem_destroy(dev);
555
556	drm_legacy_ctxbitmap_cleanup(dev);
557	drm_ht_remove(&dev->map_hash);
558	drm_fs_inode_free(dev->anon_inode);
559
560	drm_minor_free(dev, DRM_MINOR_PRIMARY);
561	drm_minor_free(dev, DRM_MINOR_RENDER);
562	drm_minor_free(dev, DRM_MINOR_CONTROL);
563
564	mutex_destroy(&dev->master_mutex);
565	mutex_destroy(&dev->ctxlist_mutex);
566	mutex_destroy(&dev->filelist_mutex);
567	mutex_destroy(&dev->struct_mutex);
568	kfree(dev->unique);
569}
570EXPORT_SYMBOL(drm_dev_fini);
571
572/**
573 * drm_dev_alloc - Allocate new DRM device
574 * @driver: DRM driver to allocate device for
575 * @parent: Parent device object
576 *
577 * Allocate and initialize a new DRM device. No device registration is done.
578 * Call drm_dev_register() to advertice the device to user space and register it
579 * with other core subsystems. This should be done last in the device
580 * initialization sequence to make sure userspace can't access an inconsistent
581 * state.
582 *
583 * The initial ref-count of the object is 1. Use drm_dev_get() and
584 * drm_dev_put() to take and drop further ref-counts.
585 *
586 * Note that for purely virtual devices @parent can be NULL.
 
 
 
 
587 *
588 * Drivers that wish to subclass or embed &struct drm_device into their
589 * own struct should look at using drm_dev_init() instead.
590 *
591 * RETURNS:
592 * Pointer to new DRM device, or ERR_PTR on failure.
593 */
594struct drm_device *drm_dev_alloc(struct drm_driver *driver,
595				 struct device *parent)
596{
 
597	struct drm_device *dev;
598	int ret;
599
600	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
601	if (!dev)
602		return ERR_PTR(-ENOMEM);
603
604	ret = drm_dev_init(dev, driver, parent);
605	if (ret) {
606		kfree(dev);
607		return ERR_PTR(ret);
608	}
609
610	return dev;
611}
612EXPORT_SYMBOL(drm_dev_alloc);
613
614static void drm_dev_release(struct kref *ref)
615{
616	struct drm_device *dev = container_of(ref, struct drm_device, ref);
617
618	if (dev->driver->release) {
619		dev->driver->release(dev);
620	} else {
621		drm_dev_fini(dev);
622		kfree(dev);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
623	}
624}
625
626/**
627 * drm_dev_get - Take reference of a DRM device
628 * @dev: device to take reference of or NULL
629 *
630 * This increases the ref-count of @dev by one. You *must* already own a
631 * reference when calling this. Use drm_dev_put() to drop this reference
632 * again.
633 *
634 * This function never fails. However, this function does not provide *any*
635 * guarantee whether the device is alive or running. It only provides a
636 * reference to the object and the memory associated with it.
637 */
638void drm_dev_get(struct drm_device *dev)
639{
640	if (dev)
641		kref_get(&dev->ref);
642}
643EXPORT_SYMBOL(drm_dev_get);
644
645/**
646 * drm_dev_put - Drop reference of a DRM device
647 * @dev: device to drop reference of or NULL
648 *
649 * This decreases the ref-count of @dev by one. The device is destroyed if the
650 * ref-count drops to zero.
651 */
652void drm_dev_put(struct drm_device *dev)
653{
654	if (dev)
655		kref_put(&dev->ref, drm_dev_release);
656}
657EXPORT_SYMBOL(drm_dev_put);
658
659/**
660 * drm_dev_unref - Drop reference of a DRM device
661 * @dev: device to drop reference of or NULL
662 *
663 * This is a compatibility alias for drm_dev_put() and should not be used by new
664 * code.
665 */
666void drm_dev_unref(struct drm_device *dev)
667{
668	drm_dev_put(dev);
669}
670EXPORT_SYMBOL(drm_dev_unref);
671
672static int create_compat_control_link(struct drm_device *dev)
673{
674	struct drm_minor *minor;
675	char *name;
676	int ret;
677
678	if (!drm_core_check_feature(dev, DRIVER_MODESET))
679		return 0;
680
681	minor = *drm_minor_get_slot(dev, DRM_MINOR_PRIMARY);
682	if (!minor)
683		return 0;
684
685	/*
686	 * Some existing userspace out there uses the existing of the controlD*
687	 * sysfs files to figure out whether it's a modeset driver. It only does
688	 * readdir, hence a symlink is sufficient (and the least confusing
689	 * option). Otherwise controlD* is entirely unused.
690	 *
691	 * Old controlD chardev have been allocated in the range
692	 * 64-127.
693	 */
694	name = kasprintf(GFP_KERNEL, "controlD%d", minor->index + 64);
695	if (!name)
696		return -ENOMEM;
697
698	ret = sysfs_create_link(minor->kdev->kobj.parent,
699				&minor->kdev->kobj,
700				name);
701
702	kfree(name);
703
704	return ret;
705}
706
707static void remove_compat_control_link(struct drm_device *dev)
708{
709	struct drm_minor *minor;
710	char *name;
711
712	if (!drm_core_check_feature(dev, DRIVER_MODESET))
713		return;
714
715	minor = *drm_minor_get_slot(dev, DRM_MINOR_PRIMARY);
716	if (!minor)
717		return;
718
719	name = kasprintf(GFP_KERNEL, "controlD%d", minor->index + 64);
720	if (!name)
721		return;
722
723	sysfs_remove_link(minor->kdev->kobj.parent, name);
724
725	kfree(name);
726}
727
728/**
729 * drm_dev_register - Register DRM device
730 * @dev: Device to register
731 * @flags: Flags passed to the driver's .load() function
732 *
733 * Register the DRM device @dev with the system, advertise device to user-space
734 * and start normal device operation. @dev must be allocated via drm_dev_alloc()
735 * previously.
736 *
737 * Never call this twice on any device!
738 *
739 * NOTE: To ensure backward compatibility with existing drivers method this
740 * function calls the &drm_driver.load method after registering the device
741 * nodes, creating race conditions. Usage of the &drm_driver.load methods is
742 * therefore deprecated, drivers must perform all initialization before calling
743 * drm_dev_register().
744 *
745 * RETURNS:
746 * 0 on success, negative error code on failure.
747 */
748int drm_dev_register(struct drm_device *dev, unsigned long flags)
749{
750	struct drm_driver *driver = dev->driver;
751	int ret;
752
753	mutex_lock(&drm_global_mutex);
754
755	ret = drm_minor_register(dev, DRM_MINOR_CONTROL);
756	if (ret)
757		goto err_minors;
758
759	ret = drm_minor_register(dev, DRM_MINOR_RENDER);
760	if (ret)
761		goto err_minors;
762
763	ret = drm_minor_register(dev, DRM_MINOR_PRIMARY);
764	if (ret)
765		goto err_minors;
766
767	ret = create_compat_control_link(dev);
768	if (ret)
769		goto err_minors;
770
771	dev->registered = true;
772
773	if (dev->driver->load) {
774		ret = dev->driver->load(dev, flags);
775		if (ret)
776			goto err_minors;
 
 
777	}
778
779	if (drm_core_check_feature(dev, DRIVER_MODESET))
780		drm_modeset_register_all(dev);
781
782	ret = 0;
783
784	DRM_INFO("Initialized %s %d.%d.%d %s for %s on minor %d\n",
785		 driver->name, driver->major, driver->minor,
786		 driver->patchlevel, driver->date,
787		 dev->dev ? dev_name(dev->dev) : "virtual device",
788		 dev->primary->index);
789
790	goto out_unlock;
791
792err_minors:
793	remove_compat_control_link(dev);
794	drm_minor_unregister(dev, DRM_MINOR_PRIMARY);
795	drm_minor_unregister(dev, DRM_MINOR_RENDER);
796	drm_minor_unregister(dev, DRM_MINOR_CONTROL);
797out_unlock:
798	mutex_unlock(&drm_global_mutex);
799	return ret;
800}
801EXPORT_SYMBOL(drm_dev_register);
802
803/**
804 * drm_dev_unregister - Unregister DRM device
805 * @dev: Device to unregister
806 *
807 * Unregister the DRM device from the system. This does the reverse of
808 * drm_dev_register() but does not deallocate the device. The caller must call
809 * drm_dev_put() to drop their final reference.
810 *
811 * A special form of unregistering for hotpluggable devices is drm_dev_unplug(),
812 * which can be called while there are still open users of @dev.
813 *
814 * This should be called first in the device teardown code to make sure
815 * userspace can't access the device instance any more.
816 */
817void drm_dev_unregister(struct drm_device *dev)
818{
819	struct drm_map_list *r_list, *list_temp;
820
821	if (drm_core_check_feature(dev, DRIVER_LEGACY))
822		drm_lastclose(dev);
823
824	dev->registered = false;
825
826	if (drm_core_check_feature(dev, DRIVER_MODESET))
827		drm_modeset_unregister_all(dev);
828
829	if (dev->driver->unload)
830		dev->driver->unload(dev);
831
832	if (dev->agp)
833		drm_pci_agp_destroy(dev);
834
835	list_for_each_entry_safe(r_list, list_temp, &dev->maplist, head)
836		drm_legacy_rmmap(dev, r_list->map);
 
 
 
 
837
838	remove_compat_control_link(dev);
839	drm_minor_unregister(dev, DRM_MINOR_PRIMARY);
840	drm_minor_unregister(dev, DRM_MINOR_RENDER);
841	drm_minor_unregister(dev, DRM_MINOR_CONTROL);
 
842}
843EXPORT_SYMBOL(drm_dev_unregister);
844
845/**
846 * drm_dev_set_unique - Set the unique name of a DRM device
847 * @dev: device of which to set the unique name
848 * @name: unique name
849 *
850 * Sets the unique name of a DRM device using the specified string. Drivers
851 * can use this at driver probe time if the unique name of the devices they
852 * drive is static.
853 *
854 * Return: 0 on success or a negative error code on failure.
855 */
856int drm_dev_set_unique(struct drm_device *dev, const char *name)
857{
858	kfree(dev->unique);
859	dev->unique = kstrdup(name, GFP_KERNEL);
860
861	return dev->unique ? 0 : -ENOMEM;
862}
863EXPORT_SYMBOL(drm_dev_set_unique);
864
865/*
866 * DRM Core
867 * The DRM core module initializes all global DRM objects and makes them
868 * available to drivers. Once setup, drivers can probe their respective
869 * devices.
870 * Currently, core management includes:
871 *  - The "DRM-Global" key/value database
872 *  - Global ID management for connectors
873 *  - DRM major number allocation
874 *  - DRM minor management
875 *  - DRM sysfs class
876 *  - DRM debugfs root
877 *
878 * Furthermore, the DRM core provides dynamic char-dev lookups. For each
879 * interface registered on a DRM device, you can request minor numbers from DRM
880 * core. DRM core takes care of major-number management and char-dev
881 * registration. A stub ->open() callback forwards any open() requests to the
882 * registered minor.
883 */
884
885static int drm_stub_open(struct inode *inode, struct file *filp)
886{
887	const struct file_operations *new_fops;
888	struct drm_minor *minor;
889	int err;
890
891	DRM_DEBUG("\n");
892
893	mutex_lock(&drm_global_mutex);
894	minor = drm_minor_acquire(iminor(inode));
895	if (IS_ERR(minor)) {
896		err = PTR_ERR(minor);
897		goto out_unlock;
898	}
899
900	new_fops = fops_get(minor->dev->driver->fops);
901	if (!new_fops) {
902		err = -ENODEV;
903		goto out_release;
904	}
905
906	replace_fops(filp, new_fops);
907	if (filp->f_op->open)
908		err = filp->f_op->open(inode, filp);
909	else
910		err = 0;
911
912out_release:
913	drm_minor_release(minor);
914out_unlock:
915	mutex_unlock(&drm_global_mutex);
916	return err;
917}
918
919static const struct file_operations drm_stub_fops = {
920	.owner = THIS_MODULE,
921	.open = drm_stub_open,
922	.llseek = noop_llseek,
923};
924
925static void drm_core_exit(void)
926{
927	unregister_chrdev(DRM_MAJOR, "drm");
928	debugfs_remove(drm_debugfs_root);
929	drm_sysfs_destroy();
930	idr_destroy(&drm_minors_idr);
931	drm_connector_ida_destroy();
932	drm_global_release();
933}
934
935static int __init drm_core_init(void)
936{
937	int ret;
938
939	drm_global_init();
940	drm_connector_ida_init();
941	idr_init(&drm_minors_idr);
942
943	ret = drm_sysfs_init();
944	if (ret < 0) {
945		DRM_ERROR("Cannot create DRM class: %d\n", ret);
946		goto error;
947	}
948
949	drm_debugfs_root = debugfs_create_dir("dri", NULL);
950	if (!drm_debugfs_root) {
951		ret = -ENOMEM;
952		DRM_ERROR("Cannot create debugfs-root: %d\n", ret);
953		goto error;
954	}
955
956	ret = register_chrdev(DRM_MAJOR, "drm", &drm_stub_fops);
957	if (ret < 0)
958		goto error;
959
960	drm_core_init_complete = true;
961
962	DRM_DEBUG("Initialized\n");
963	return 0;
964
965error:
966	drm_core_exit();
967	return ret;
968}
969
970module_init(drm_core_init);
971module_exit(drm_core_exit);