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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
40unsigned int drm_debug = 0; /* bitmask of DRM_UT_x */
41EXPORT_SYMBOL(drm_debug);
42
43MODULE_AUTHOR(CORE_AUTHOR);
44MODULE_DESCRIPTION(CORE_DESC);
45MODULE_LICENSE("GPL and additional rights");
46MODULE_PARM_DESC(debug, "Enable debug output");
47module_param_named(debug, drm_debug, int, 0600);
48
49static DEFINE_SPINLOCK(drm_minor_lock);
50static struct idr drm_minors_idr;
51
52static struct dentry *drm_debugfs_root;
53
54void drm_err(const char *format, ...)
55{
56 struct va_format vaf;
57 va_list args;
58
59 va_start(args, format);
60
61 vaf.fmt = format;
62 vaf.va = &args;
63
64 printk(KERN_ERR "[" DRM_NAME ":%ps] *ERROR* %pV",
65 __builtin_return_address(0), &vaf);
66
67 va_end(args);
68}
69EXPORT_SYMBOL(drm_err);
70
71void drm_ut_debug_printk(const char *function_name, const char *format, ...)
72{
73 struct va_format vaf;
74 va_list args;
75
76 va_start(args, format);
77 vaf.fmt = format;
78 vaf.va = &args;
79
80 printk(KERN_DEBUG "[" DRM_NAME ":%s] %pV", function_name, &vaf);
81
82 va_end(args);
83}
84EXPORT_SYMBOL(drm_ut_debug_printk);
85
86struct drm_master *drm_master_create(struct drm_minor *minor)
87{
88 struct drm_master *master;
89
90 master = kzalloc(sizeof(*master), GFP_KERNEL);
91 if (!master)
92 return NULL;
93
94 kref_init(&master->refcount);
95 spin_lock_init(&master->lock.spinlock);
96 init_waitqueue_head(&master->lock.lock_queue);
97 idr_init(&master->magic_map);
98 master->minor = minor;
99
100 return master;
101}
102
103struct drm_master *drm_master_get(struct drm_master *master)
104{
105 kref_get(&master->refcount);
106 return master;
107}
108EXPORT_SYMBOL(drm_master_get);
109
110static void drm_master_destroy(struct kref *kref)
111{
112 struct drm_master *master = container_of(kref, struct drm_master, refcount);
113 struct drm_device *dev = master->minor->dev;
114 struct drm_map_list *r_list, *list_temp;
115
116 mutex_lock(&dev->struct_mutex);
117 if (dev->driver->master_destroy)
118 dev->driver->master_destroy(dev, master);
119
120 list_for_each_entry_safe(r_list, list_temp, &dev->maplist, head) {
121 if (r_list->master == master) {
122 drm_legacy_rmmap_locked(dev, r_list->map);
123 r_list = NULL;
124 }
125 }
126 mutex_unlock(&dev->struct_mutex);
127
128 idr_destroy(&master->magic_map);
129 kfree(master->unique);
130 kfree(master);
131}
132
133void drm_master_put(struct drm_master **master)
134{
135 kref_put(&(*master)->refcount, drm_master_destroy);
136 *master = NULL;
137}
138EXPORT_SYMBOL(drm_master_put);
139
140int drm_setmaster_ioctl(struct drm_device *dev, void *data,
141 struct drm_file *file_priv)
142{
143 int ret = 0;
144
145 mutex_lock(&dev->master_mutex);
146 if (file_priv->is_master)
147 goto out_unlock;
148
149 if (file_priv->minor->master) {
150 ret = -EINVAL;
151 goto out_unlock;
152 }
153
154 if (!file_priv->master) {
155 ret = -EINVAL;
156 goto out_unlock;
157 }
158
159 if (!file_priv->allowed_master) {
160 ret = drm_new_set_master(dev, file_priv);
161 goto out_unlock;
162 }
163
164 file_priv->minor->master = drm_master_get(file_priv->master);
165 file_priv->is_master = 1;
166 if (dev->driver->master_set) {
167 ret = dev->driver->master_set(dev, file_priv, false);
168 if (unlikely(ret != 0)) {
169 file_priv->is_master = 0;
170 drm_master_put(&file_priv->minor->master);
171 }
172 }
173
174out_unlock:
175 mutex_unlock(&dev->master_mutex);
176 return ret;
177}
178
179int drm_dropmaster_ioctl(struct drm_device *dev, void *data,
180 struct drm_file *file_priv)
181{
182 int ret = -EINVAL;
183
184 mutex_lock(&dev->master_mutex);
185 if (!file_priv->is_master)
186 goto out_unlock;
187
188 if (!file_priv->minor->master)
189 goto out_unlock;
190
191 ret = 0;
192 if (dev->driver->master_drop)
193 dev->driver->master_drop(dev, file_priv, false);
194 drm_master_put(&file_priv->minor->master);
195 file_priv->is_master = 0;
196
197out_unlock:
198 mutex_unlock(&dev->master_mutex);
199 return ret;
200}
201
202/*
203 * DRM Minors
204 * A DRM device can provide several char-dev interfaces on the DRM-Major. Each
205 * of them is represented by a drm_minor object. Depending on the capabilities
206 * of the device-driver, different interfaces are registered.
207 *
208 * Minors can be accessed via dev->$minor_name. This pointer is either
209 * NULL or a valid drm_minor pointer and stays valid as long as the device is
210 * valid. This means, DRM minors have the same life-time as the underlying
211 * device. However, this doesn't mean that the minor is active. Minors are
212 * registered and unregistered dynamically according to device-state.
213 */
214
215static struct drm_minor **drm_minor_get_slot(struct drm_device *dev,
216 unsigned int type)
217{
218 switch (type) {
219 case DRM_MINOR_LEGACY:
220 return &dev->primary;
221 case DRM_MINOR_RENDER:
222 return &dev->render;
223 case DRM_MINOR_CONTROL:
224 return &dev->control;
225 default:
226 return NULL;
227 }
228}
229
230static int drm_minor_alloc(struct drm_device *dev, unsigned int type)
231{
232 struct drm_minor *minor;
233 unsigned long flags;
234 int r;
235
236 minor = kzalloc(sizeof(*minor), GFP_KERNEL);
237 if (!minor)
238 return -ENOMEM;
239
240 minor->type = type;
241 minor->dev = dev;
242
243 idr_preload(GFP_KERNEL);
244 spin_lock_irqsave(&drm_minor_lock, flags);
245 r = idr_alloc(&drm_minors_idr,
246 NULL,
247 64 * type,
248 64 * (type + 1),
249 GFP_NOWAIT);
250 spin_unlock_irqrestore(&drm_minor_lock, flags);
251 idr_preload_end();
252
253 if (r < 0)
254 goto err_free;
255
256 minor->index = r;
257
258 minor->kdev = drm_sysfs_minor_alloc(minor);
259 if (IS_ERR(minor->kdev)) {
260 r = PTR_ERR(minor->kdev);
261 goto err_index;
262 }
263
264 *drm_minor_get_slot(dev, type) = minor;
265 return 0;
266
267err_index:
268 spin_lock_irqsave(&drm_minor_lock, flags);
269 idr_remove(&drm_minors_idr, minor->index);
270 spin_unlock_irqrestore(&drm_minor_lock, flags);
271err_free:
272 kfree(minor);
273 return r;
274}
275
276static void drm_minor_free(struct drm_device *dev, unsigned int type)
277{
278 struct drm_minor **slot, *minor;
279 unsigned long flags;
280
281 slot = drm_minor_get_slot(dev, type);
282 minor = *slot;
283 if (!minor)
284 return;
285
286 put_device(minor->kdev);
287
288 spin_lock_irqsave(&drm_minor_lock, flags);
289 idr_remove(&drm_minors_idr, minor->index);
290 spin_unlock_irqrestore(&drm_minor_lock, flags);
291
292 kfree(minor);
293 *slot = NULL;
294}
295
296static int drm_minor_register(struct drm_device *dev, unsigned int type)
297{
298 struct drm_minor *minor;
299 unsigned long flags;
300 int ret;
301
302 DRM_DEBUG("\n");
303
304 minor = *drm_minor_get_slot(dev, type);
305 if (!minor)
306 return 0;
307
308 ret = drm_debugfs_init(minor, minor->index, drm_debugfs_root);
309 if (ret) {
310 DRM_ERROR("DRM: Failed to initialize /sys/kernel/debug/dri.\n");
311 return ret;
312 }
313
314 ret = device_add(minor->kdev);
315 if (ret)
316 goto err_debugfs;
317
318 /* replace NULL with @minor so lookups will succeed from now on */
319 spin_lock_irqsave(&drm_minor_lock, flags);
320 idr_replace(&drm_minors_idr, minor, minor->index);
321 spin_unlock_irqrestore(&drm_minor_lock, flags);
322
323 DRM_DEBUG("new minor registered %d\n", minor->index);
324 return 0;
325
326err_debugfs:
327 drm_debugfs_cleanup(minor);
328 return ret;
329}
330
331static void drm_minor_unregister(struct drm_device *dev, unsigned int type)
332{
333 struct drm_minor *minor;
334 unsigned long flags;
335
336 minor = *drm_minor_get_slot(dev, type);
337 if (!minor || !device_is_registered(minor->kdev))
338 return;
339
340 /* replace @minor with NULL so lookups will fail from now on */
341 spin_lock_irqsave(&drm_minor_lock, flags);
342 idr_replace(&drm_minors_idr, NULL, minor->index);
343 spin_unlock_irqrestore(&drm_minor_lock, flags);
344
345 device_del(minor->kdev);
346 dev_set_drvdata(minor->kdev, NULL); /* safety belt */
347 drm_debugfs_cleanup(minor);
348}
349
350/**
351 * drm_minor_acquire - Acquire a DRM minor
352 * @minor_id: Minor ID of the DRM-minor
353 *
354 * Looks up the given minor-ID and returns the respective DRM-minor object. The
355 * refence-count of the underlying device is increased so you must release this
356 * object with drm_minor_release().
357 *
358 * As long as you hold this minor, it is guaranteed that the object and the
359 * minor->dev pointer will stay valid! However, the device may get unplugged and
360 * unregistered while you hold the minor.
361 *
362 * Returns:
363 * Pointer to minor-object with increased device-refcount, or PTR_ERR on
364 * failure.
365 */
366struct drm_minor *drm_minor_acquire(unsigned int minor_id)
367{
368 struct drm_minor *minor;
369 unsigned long flags;
370
371 spin_lock_irqsave(&drm_minor_lock, flags);
372 minor = idr_find(&drm_minors_idr, minor_id);
373 if (minor)
374 drm_dev_ref(minor->dev);
375 spin_unlock_irqrestore(&drm_minor_lock, flags);
376
377 if (!minor) {
378 return ERR_PTR(-ENODEV);
379 } else if (drm_device_is_unplugged(minor->dev)) {
380 drm_dev_unref(minor->dev);
381 return ERR_PTR(-ENODEV);
382 }
383
384 return minor;
385}
386
387/**
388 * drm_minor_release - Release DRM minor
389 * @minor: Pointer to DRM minor object
390 *
391 * Release a minor that was previously acquired via drm_minor_acquire().
392 */
393void drm_minor_release(struct drm_minor *minor)
394{
395 drm_dev_unref(minor->dev);
396}
397
398/**
399 * DOC: driver instance overview
400 *
401 * A device instance for a drm driver is represented by struct &drm_device. This
402 * is allocated with drm_dev_alloc(), usually from bus-specific ->probe()
403 * callbacks implemented by the driver. The driver then needs to initialize all
404 * the various subsystems for the drm device like memory management, vblank
405 * handling, modesetting support and intial output configuration plus obviously
406 * initialize all the corresponding hardware bits. An important part of this is
407 * also calling drm_dev_set_unique() to set the userspace-visible unique name of
408 * this device instance. Finally when everything is up and running and ready for
409 * userspace the device instance can be published using drm_dev_register().
410 *
411 * There is also deprecated support for initalizing device instances using
412 * bus-specific helpers and the ->load() callback. But due to
413 * backwards-compatibility needs the device instance have to be published too
414 * early, which requires unpretty global locking to make safe and is therefore
415 * only support for existing drivers not yet converted to the new scheme.
416 *
417 * When cleaning up a device instance everything needs to be done in reverse:
418 * First unpublish the device instance with drm_dev_unregister(). Then clean up
419 * any other resources allocated at device initialization and drop the driver's
420 * reference to &drm_device using drm_dev_unref().
421 *
422 * Note that the lifetime rules for &drm_device instance has still a lot of
423 * historical baggage. Hence use the reference counting provided by
424 * drm_dev_ref() and drm_dev_unref() only carefully.
425 *
426 * Also note that embedding of &drm_device is currently not (yet) supported (but
427 * it would be easy to add). Drivers can store driver-private data in the
428 * dev_priv field of &drm_device.
429 */
430
431/**
432 * drm_put_dev - Unregister and release a DRM device
433 * @dev: DRM device
434 *
435 * Called at module unload time or when a PCI device is unplugged.
436 *
437 * Cleans up all DRM device, calling drm_lastclose().
438 *
439 * Note: Use of this function is deprecated. It will eventually go away
440 * completely. Please use drm_dev_unregister() and drm_dev_unref() explicitly
441 * instead to make sure that the device isn't userspace accessible any more
442 * while teardown is in progress, ensuring that userspace can't access an
443 * inconsistent state.
444 */
445void drm_put_dev(struct drm_device *dev)
446{
447 DRM_DEBUG("\n");
448
449 if (!dev) {
450 DRM_ERROR("cleanup called no dev\n");
451 return;
452 }
453
454 drm_dev_unregister(dev);
455 drm_dev_unref(dev);
456}
457EXPORT_SYMBOL(drm_put_dev);
458
459void drm_unplug_dev(struct drm_device *dev)
460{
461 /* for a USB device */
462 drm_minor_unregister(dev, DRM_MINOR_LEGACY);
463 drm_minor_unregister(dev, DRM_MINOR_RENDER);
464 drm_minor_unregister(dev, DRM_MINOR_CONTROL);
465
466 mutex_lock(&drm_global_mutex);
467
468 drm_device_set_unplugged(dev);
469
470 if (dev->open_count == 0) {
471 drm_put_dev(dev);
472 }
473 mutex_unlock(&drm_global_mutex);
474}
475EXPORT_SYMBOL(drm_unplug_dev);
476
477/*
478 * DRM internal mount
479 * We want to be able to allocate our own "struct address_space" to control
480 * memory-mappings in VRAM (or stolen RAM, ...). However, core MM does not allow
481 * stand-alone address_space objects, so we need an underlying inode. As there
482 * is no way to allocate an independent inode easily, we need a fake internal
483 * VFS mount-point.
484 *
485 * The drm_fs_inode_new() function allocates a new inode, drm_fs_inode_free()
486 * frees it again. You are allowed to use iget() and iput() to get references to
487 * the inode. But each drm_fs_inode_new() call must be paired with exactly one
488 * drm_fs_inode_free() call (which does not have to be the last iput()).
489 * We use drm_fs_inode_*() to manage our internal VFS mount-point and share it
490 * between multiple inode-users. You could, technically, call
491 * iget() + drm_fs_inode_free() directly after alloc and sometime later do an
492 * iput(), but this way you'd end up with a new vfsmount for each inode.
493 */
494
495static int drm_fs_cnt;
496static struct vfsmount *drm_fs_mnt;
497
498static const struct dentry_operations drm_fs_dops = {
499 .d_dname = simple_dname,
500};
501
502static const struct super_operations drm_fs_sops = {
503 .statfs = simple_statfs,
504};
505
506static struct dentry *drm_fs_mount(struct file_system_type *fs_type, int flags,
507 const char *dev_name, void *data)
508{
509 return mount_pseudo(fs_type,
510 "drm:",
511 &drm_fs_sops,
512 &drm_fs_dops,
513 0x010203ff);
514}
515
516static struct file_system_type drm_fs_type = {
517 .name = "drm",
518 .owner = THIS_MODULE,
519 .mount = drm_fs_mount,
520 .kill_sb = kill_anon_super,
521};
522
523static struct inode *drm_fs_inode_new(void)
524{
525 struct inode *inode;
526 int r;
527
528 r = simple_pin_fs(&drm_fs_type, &drm_fs_mnt, &drm_fs_cnt);
529 if (r < 0) {
530 DRM_ERROR("Cannot mount pseudo fs: %d\n", r);
531 return ERR_PTR(r);
532 }
533
534 inode = alloc_anon_inode(drm_fs_mnt->mnt_sb);
535 if (IS_ERR(inode))
536 simple_release_fs(&drm_fs_mnt, &drm_fs_cnt);
537
538 return inode;
539}
540
541static void drm_fs_inode_free(struct inode *inode)
542{
543 if (inode) {
544 iput(inode);
545 simple_release_fs(&drm_fs_mnt, &drm_fs_cnt);
546 }
547}
548
549/**
550 * drm_dev_alloc - Allocate new DRM device
551 * @driver: DRM driver to allocate device for
552 * @parent: Parent device object
553 *
554 * Allocate and initialize a new DRM device. No device registration is done.
555 * Call drm_dev_register() to advertice the device to user space and register it
556 * with other core subsystems. This should be done last in the device
557 * initialization sequence to make sure userspace can't access an inconsistent
558 * state.
559 *
560 * The initial ref-count of the object is 1. Use drm_dev_ref() and
561 * drm_dev_unref() to take and drop further ref-counts.
562 *
563 * Note that for purely virtual devices @parent can be NULL.
564 *
565 * RETURNS:
566 * Pointer to new DRM device, or NULL if out of memory.
567 */
568struct drm_device *drm_dev_alloc(struct drm_driver *driver,
569 struct device *parent)
570{
571 struct drm_device *dev;
572 int ret;
573
574 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
575 if (!dev)
576 return NULL;
577
578 kref_init(&dev->ref);
579 dev->dev = parent;
580 dev->driver = driver;
581
582 INIT_LIST_HEAD(&dev->filelist);
583 INIT_LIST_HEAD(&dev->ctxlist);
584 INIT_LIST_HEAD(&dev->vmalist);
585 INIT_LIST_HEAD(&dev->maplist);
586 INIT_LIST_HEAD(&dev->vblank_event_list);
587
588 spin_lock_init(&dev->buf_lock);
589 spin_lock_init(&dev->event_lock);
590 mutex_init(&dev->struct_mutex);
591 mutex_init(&dev->ctxlist_mutex);
592 mutex_init(&dev->master_mutex);
593
594 dev->anon_inode = drm_fs_inode_new();
595 if (IS_ERR(dev->anon_inode)) {
596 ret = PTR_ERR(dev->anon_inode);
597 DRM_ERROR("Cannot allocate anonymous inode: %d\n", ret);
598 goto err_free;
599 }
600
601 if (drm_core_check_feature(dev, DRIVER_MODESET)) {
602 ret = drm_minor_alloc(dev, DRM_MINOR_CONTROL);
603 if (ret)
604 goto err_minors;
605
606 WARN_ON(driver->suspend || driver->resume);
607 }
608
609 if (drm_core_check_feature(dev, DRIVER_RENDER)) {
610 ret = drm_minor_alloc(dev, DRM_MINOR_RENDER);
611 if (ret)
612 goto err_minors;
613 }
614
615 ret = drm_minor_alloc(dev, DRM_MINOR_LEGACY);
616 if (ret)
617 goto err_minors;
618
619 if (drm_ht_create(&dev->map_hash, 12))
620 goto err_minors;
621
622 drm_legacy_ctxbitmap_init(dev);
623
624 if (drm_core_check_feature(dev, DRIVER_GEM)) {
625 ret = drm_gem_init(dev);
626 if (ret) {
627 DRM_ERROR("Cannot initialize graphics execution manager (GEM)\n");
628 goto err_ctxbitmap;
629 }
630 }
631
632 if (parent) {
633 ret = drm_dev_set_unique(dev, dev_name(parent));
634 if (ret)
635 goto err_setunique;
636 }
637
638 return dev;
639
640err_setunique:
641 if (drm_core_check_feature(dev, DRIVER_GEM))
642 drm_gem_destroy(dev);
643err_ctxbitmap:
644 drm_legacy_ctxbitmap_cleanup(dev);
645 drm_ht_remove(&dev->map_hash);
646err_minors:
647 drm_minor_free(dev, DRM_MINOR_LEGACY);
648 drm_minor_free(dev, DRM_MINOR_RENDER);
649 drm_minor_free(dev, DRM_MINOR_CONTROL);
650 drm_fs_inode_free(dev->anon_inode);
651err_free:
652 mutex_destroy(&dev->master_mutex);
653 kfree(dev);
654 return NULL;
655}
656EXPORT_SYMBOL(drm_dev_alloc);
657
658static void drm_dev_release(struct kref *ref)
659{
660 struct drm_device *dev = container_of(ref, struct drm_device, ref);
661
662 if (drm_core_check_feature(dev, DRIVER_GEM))
663 drm_gem_destroy(dev);
664
665 drm_legacy_ctxbitmap_cleanup(dev);
666 drm_ht_remove(&dev->map_hash);
667 drm_fs_inode_free(dev->anon_inode);
668
669 drm_minor_free(dev, DRM_MINOR_LEGACY);
670 drm_minor_free(dev, DRM_MINOR_RENDER);
671 drm_minor_free(dev, DRM_MINOR_CONTROL);
672
673 mutex_destroy(&dev->master_mutex);
674 kfree(dev->unique);
675 kfree(dev);
676}
677
678/**
679 * drm_dev_ref - Take reference of a DRM device
680 * @dev: device to take reference of or NULL
681 *
682 * This increases the ref-count of @dev by one. You *must* already own a
683 * reference when calling this. Use drm_dev_unref() to drop this reference
684 * again.
685 *
686 * This function never fails. However, this function does not provide *any*
687 * guarantee whether the device is alive or running. It only provides a
688 * reference to the object and the memory associated with it.
689 */
690void drm_dev_ref(struct drm_device *dev)
691{
692 if (dev)
693 kref_get(&dev->ref);
694}
695EXPORT_SYMBOL(drm_dev_ref);
696
697/**
698 * drm_dev_unref - Drop reference of a DRM device
699 * @dev: device to drop reference of or NULL
700 *
701 * This decreases the ref-count of @dev by one. The device is destroyed if the
702 * ref-count drops to zero.
703 */
704void drm_dev_unref(struct drm_device *dev)
705{
706 if (dev)
707 kref_put(&dev->ref, drm_dev_release);
708}
709EXPORT_SYMBOL(drm_dev_unref);
710
711/**
712 * drm_dev_register - Register DRM device
713 * @dev: Device to register
714 * @flags: Flags passed to the driver's .load() function
715 *
716 * Register the DRM device @dev with the system, advertise device to user-space
717 * and start normal device operation. @dev must be allocated via drm_dev_alloc()
718 * previously.
719 *
720 * Never call this twice on any device!
721 *
722 * NOTE: To ensure backward compatibility with existing drivers method this
723 * function calls the ->load() method after registering the device nodes,
724 * creating race conditions. Usage of the ->load() methods is therefore
725 * deprecated, drivers must perform all initialization before calling
726 * drm_dev_register().
727 *
728 * RETURNS:
729 * 0 on success, negative error code on failure.
730 */
731int drm_dev_register(struct drm_device *dev, unsigned long flags)
732{
733 int ret;
734
735 mutex_lock(&drm_global_mutex);
736
737 ret = drm_minor_register(dev, DRM_MINOR_CONTROL);
738 if (ret)
739 goto err_minors;
740
741 ret = drm_minor_register(dev, DRM_MINOR_RENDER);
742 if (ret)
743 goto err_minors;
744
745 ret = drm_minor_register(dev, DRM_MINOR_LEGACY);
746 if (ret)
747 goto err_minors;
748
749 if (dev->driver->load) {
750 ret = dev->driver->load(dev, flags);
751 if (ret)
752 goto err_minors;
753 }
754
755 ret = 0;
756 goto out_unlock;
757
758err_minors:
759 drm_minor_unregister(dev, DRM_MINOR_LEGACY);
760 drm_minor_unregister(dev, DRM_MINOR_RENDER);
761 drm_minor_unregister(dev, DRM_MINOR_CONTROL);
762out_unlock:
763 mutex_unlock(&drm_global_mutex);
764 return ret;
765}
766EXPORT_SYMBOL(drm_dev_register);
767
768/**
769 * drm_dev_unregister - Unregister DRM device
770 * @dev: Device to unregister
771 *
772 * Unregister the DRM device from the system. This does the reverse of
773 * drm_dev_register() but does not deallocate the device. The caller must call
774 * drm_dev_unref() to drop their final reference.
775 *
776 * This should be called first in the device teardown code to make sure
777 * userspace can't access the device instance any more.
778 */
779void drm_dev_unregister(struct drm_device *dev)
780{
781 struct drm_map_list *r_list, *list_temp;
782
783 drm_lastclose(dev);
784
785 if (dev->driver->unload)
786 dev->driver->unload(dev);
787
788 if (dev->agp)
789 drm_pci_agp_destroy(dev);
790
791 drm_vblank_cleanup(dev);
792
793 list_for_each_entry_safe(r_list, list_temp, &dev->maplist, head)
794 drm_legacy_rmmap(dev, r_list->map);
795
796 drm_minor_unregister(dev, DRM_MINOR_LEGACY);
797 drm_minor_unregister(dev, DRM_MINOR_RENDER);
798 drm_minor_unregister(dev, DRM_MINOR_CONTROL);
799}
800EXPORT_SYMBOL(drm_dev_unregister);
801
802/**
803 * drm_dev_set_unique - Set the unique name of a DRM device
804 * @dev: device of which to set the unique name
805 * @name: unique name
806 *
807 * Sets the unique name of a DRM device using the specified string. Drivers
808 * can use this at driver probe time if the unique name of the devices they
809 * drive is static.
810 *
811 * Return: 0 on success or a negative error code on failure.
812 */
813int drm_dev_set_unique(struct drm_device *dev, const char *name)
814{
815 kfree(dev->unique);
816 dev->unique = kstrdup(name, GFP_KERNEL);
817
818 return dev->unique ? 0 : -ENOMEM;
819}
820EXPORT_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
842static 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
869out_release:
870 drm_minor_release(minor);
871out_unlock:
872 mutex_unlock(&drm_global_mutex);
873 return err;
874}
875
876static const struct file_operations drm_stub_fops = {
877 .owner = THIS_MODULE,
878 .open = drm_stub_open,
879 .llseek = noop_llseek,
880};
881
882static 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;
909err_p3:
910 drm_sysfs_destroy();
911err_p2:
912 unregister_chrdev(DRM_MAJOR, "drm");
913
914 idr_destroy(&drm_minors_idr);
915err_p1:
916 return ret;
917}
918
919static 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
930module_init(drm_core_init);
931module_exit(drm_core_exit);
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/pseudo_fs.h>
35#include <linux/slab.h>
36#include <linux/srcu.h>
37
38#include <drm/drm_client.h>
39#include <drm/drm_color_mgmt.h>
40#include <drm/drm_drv.h>
41#include <drm/drm_file.h>
42#include <drm/drm_managed.h>
43#include <drm/drm_mode_object.h>
44#include <drm/drm_print.h>
45
46#include "drm_crtc_internal.h"
47#include "drm_internal.h"
48#include "drm_legacy.h"
49
50MODULE_AUTHOR("Gareth Hughes, Leif Delgass, José Fonseca, Jon Smirl");
51MODULE_DESCRIPTION("DRM shared core routines");
52MODULE_LICENSE("GPL and additional rights");
53
54static DEFINE_SPINLOCK(drm_minor_lock);
55static struct idr drm_minors_idr;
56
57/*
58 * If the drm core fails to init for whatever reason,
59 * we should prevent any drivers from registering with it.
60 * It's best to check this at drm_dev_init(), as some drivers
61 * prefer to embed struct drm_device into their own device
62 * structure and call drm_dev_init() themselves.
63 */
64static bool drm_core_init_complete = false;
65
66static struct dentry *drm_debugfs_root;
67
68DEFINE_STATIC_SRCU(drm_unplug_srcu);
69
70/*
71 * DRM Minors
72 * A DRM device can provide several char-dev interfaces on the DRM-Major. Each
73 * of them is represented by a drm_minor object. Depending on the capabilities
74 * of the device-driver, different interfaces are registered.
75 *
76 * Minors can be accessed via dev->$minor_name. This pointer is either
77 * NULL or a valid drm_minor pointer and stays valid as long as the device is
78 * valid. This means, DRM minors have the same life-time as the underlying
79 * device. However, this doesn't mean that the minor is active. Minors are
80 * registered and unregistered dynamically according to device-state.
81 */
82
83static struct drm_minor **drm_minor_get_slot(struct drm_device *dev,
84 unsigned int type)
85{
86 switch (type) {
87 case DRM_MINOR_PRIMARY:
88 return &dev->primary;
89 case DRM_MINOR_RENDER:
90 return &dev->render;
91 default:
92 BUG();
93 }
94}
95
96static void drm_minor_alloc_release(struct drm_device *dev, void *data)
97{
98 struct drm_minor *minor = data;
99 unsigned long flags;
100
101 WARN_ON(dev != minor->dev);
102
103 put_device(minor->kdev);
104
105 spin_lock_irqsave(&drm_minor_lock, flags);
106 idr_remove(&drm_minors_idr, minor->index);
107 spin_unlock_irqrestore(&drm_minor_lock, flags);
108}
109
110static int drm_minor_alloc(struct drm_device *dev, unsigned int type)
111{
112 struct drm_minor *minor;
113 unsigned long flags;
114 int r;
115
116 minor = drmm_kzalloc(dev, sizeof(*minor), GFP_KERNEL);
117 if (!minor)
118 return -ENOMEM;
119
120 minor->type = type;
121 minor->dev = dev;
122
123 idr_preload(GFP_KERNEL);
124 spin_lock_irqsave(&drm_minor_lock, flags);
125 r = idr_alloc(&drm_minors_idr,
126 NULL,
127 64 * type,
128 64 * (type + 1),
129 GFP_NOWAIT);
130 spin_unlock_irqrestore(&drm_minor_lock, flags);
131 idr_preload_end();
132
133 if (r < 0)
134 return r;
135
136 minor->index = r;
137
138 r = drmm_add_action_or_reset(dev, drm_minor_alloc_release, minor);
139 if (r)
140 return r;
141
142 minor->kdev = drm_sysfs_minor_alloc(minor);
143 if (IS_ERR(minor->kdev))
144 return PTR_ERR(minor->kdev);
145
146 *drm_minor_get_slot(dev, type) = minor;
147 return 0;
148}
149
150static int drm_minor_register(struct drm_device *dev, unsigned int type)
151{
152 struct drm_minor *minor;
153 unsigned long flags;
154 int ret;
155
156 DRM_DEBUG("\n");
157
158 minor = *drm_minor_get_slot(dev, type);
159 if (!minor)
160 return 0;
161
162 ret = drm_debugfs_init(minor, minor->index, drm_debugfs_root);
163 if (ret) {
164 DRM_ERROR("DRM: Failed to initialize /sys/kernel/debug/dri.\n");
165 goto err_debugfs;
166 }
167
168 ret = device_add(minor->kdev);
169 if (ret)
170 goto err_debugfs;
171
172 /* replace NULL with @minor so lookups will succeed from now on */
173 spin_lock_irqsave(&drm_minor_lock, flags);
174 idr_replace(&drm_minors_idr, minor, minor->index);
175 spin_unlock_irqrestore(&drm_minor_lock, flags);
176
177 DRM_DEBUG("new minor registered %d\n", minor->index);
178 return 0;
179
180err_debugfs:
181 drm_debugfs_cleanup(minor);
182 return ret;
183}
184
185static void drm_minor_unregister(struct drm_device *dev, unsigned int type)
186{
187 struct drm_minor *minor;
188 unsigned long flags;
189
190 minor = *drm_minor_get_slot(dev, type);
191 if (!minor || !device_is_registered(minor->kdev))
192 return;
193
194 /* replace @minor with NULL so lookups will fail from now on */
195 spin_lock_irqsave(&drm_minor_lock, flags);
196 idr_replace(&drm_minors_idr, NULL, minor->index);
197 spin_unlock_irqrestore(&drm_minor_lock, flags);
198
199 device_del(minor->kdev);
200 dev_set_drvdata(minor->kdev, NULL); /* safety belt */
201 drm_debugfs_cleanup(minor);
202}
203
204/*
205 * Looks up the given minor-ID and returns the respective DRM-minor object. The
206 * refence-count of the underlying device is increased so you must release this
207 * object with drm_minor_release().
208 *
209 * As long as you hold this minor, it is guaranteed that the object and the
210 * minor->dev pointer will stay valid! However, the device may get unplugged and
211 * unregistered while you hold the minor.
212 */
213struct drm_minor *drm_minor_acquire(unsigned int minor_id)
214{
215 struct drm_minor *minor;
216 unsigned long flags;
217
218 spin_lock_irqsave(&drm_minor_lock, flags);
219 minor = idr_find(&drm_minors_idr, minor_id);
220 if (minor)
221 drm_dev_get(minor->dev);
222 spin_unlock_irqrestore(&drm_minor_lock, flags);
223
224 if (!minor) {
225 return ERR_PTR(-ENODEV);
226 } else if (drm_dev_is_unplugged(minor->dev)) {
227 drm_dev_put(minor->dev);
228 return ERR_PTR(-ENODEV);
229 }
230
231 return minor;
232}
233
234void drm_minor_release(struct drm_minor *minor)
235{
236 drm_dev_put(minor->dev);
237}
238
239/**
240 * DOC: driver instance overview
241 *
242 * A device instance for a drm driver is represented by &struct drm_device. This
243 * is initialized with drm_dev_init(), usually from bus-specific ->probe()
244 * callbacks implemented by the driver. The driver then needs to initialize all
245 * the various subsystems for the drm device like memory management, vblank
246 * handling, modesetting support and intial output configuration plus obviously
247 * initialize all the corresponding hardware bits. Finally when everything is up
248 * and running and ready for userspace the device instance can be published
249 * using drm_dev_register().
250 *
251 * There is also deprecated support for initalizing device instances using
252 * bus-specific helpers and the &drm_driver.load callback. But due to
253 * backwards-compatibility needs the device instance have to be published too
254 * early, which requires unpretty global locking to make safe and is therefore
255 * only support for existing drivers not yet converted to the new scheme.
256 *
257 * When cleaning up a device instance everything needs to be done in reverse:
258 * First unpublish the device instance with drm_dev_unregister(). Then clean up
259 * any other resources allocated at device initialization and drop the driver's
260 * reference to &drm_device using drm_dev_put().
261 *
262 * Note that any allocation or resource which is visible to userspace must be
263 * released only when the final drm_dev_put() is called, and not when the
264 * driver is unbound from the underlying physical struct &device. Best to use
265 * &drm_device managed resources with drmm_add_action(), drmm_kmalloc() and
266 * related functions.
267 *
268 * devres managed resources like devm_kmalloc() can only be used for resources
269 * directly related to the underlying hardware device, and only used in code
270 * paths fully protected by drm_dev_enter() and drm_dev_exit().
271 *
272 * Display driver example
273 * ~~~~~~~~~~~~~~~~~~~~~~
274 *
275 * The following example shows a typical structure of a DRM display driver.
276 * The example focus on the probe() function and the other functions that is
277 * almost always present and serves as a demonstration of devm_drm_dev_init().
278 *
279 * .. code-block:: c
280 *
281 * struct driver_device {
282 * struct drm_device drm;
283 * void *userspace_facing;
284 * struct clk *pclk;
285 * };
286 *
287 * static struct drm_driver driver_drm_driver = {
288 * [...]
289 * };
290 *
291 * static int driver_probe(struct platform_device *pdev)
292 * {
293 * struct driver_device *priv;
294 * struct drm_device *drm;
295 * int ret;
296 *
297 * // devm_kzalloc() can't be used here because the drm_device '
298 * // lifetime can exceed the device lifetime if driver unbind
299 * // happens when userspace still has open file descriptors.
300 * priv = kzalloc(sizeof(*priv), GFP_KERNEL);
301 * if (!priv)
302 * return -ENOMEM;
303 *
304 * drm = &priv->drm;
305 *
306 * ret = devm_drm_dev_init(&pdev->dev, drm, &driver_drm_driver);
307 * if (ret) {
308 * kfree(priv);
309 * return ret;
310 * }
311 * drmm_add_final_kfree(drm, priv);
312 *
313 * ret = drmm_mode_config_init(drm);
314 * if (ret)
315 * return ret;
316 *
317 * priv->userspace_facing = drmm_kzalloc(..., GFP_KERNEL);
318 * if (!priv->userspace_facing)
319 * return -ENOMEM;
320 *
321 * priv->pclk = devm_clk_get(dev, "PCLK");
322 * if (IS_ERR(priv->pclk))
323 * return PTR_ERR(priv->pclk);
324 *
325 * // Further setup, display pipeline etc
326 *
327 * platform_set_drvdata(pdev, drm);
328 *
329 * drm_mode_config_reset(drm);
330 *
331 * ret = drm_dev_register(drm);
332 * if (ret)
333 * return ret;
334 *
335 * drm_fbdev_generic_setup(drm, 32);
336 *
337 * return 0;
338 * }
339 *
340 * // This function is called before the devm_ resources are released
341 * static int driver_remove(struct platform_device *pdev)
342 * {
343 * struct drm_device *drm = platform_get_drvdata(pdev);
344 *
345 * drm_dev_unregister(drm);
346 * drm_atomic_helper_shutdown(drm)
347 *
348 * return 0;
349 * }
350 *
351 * // This function is called on kernel restart and shutdown
352 * static void driver_shutdown(struct platform_device *pdev)
353 * {
354 * drm_atomic_helper_shutdown(platform_get_drvdata(pdev));
355 * }
356 *
357 * static int __maybe_unused driver_pm_suspend(struct device *dev)
358 * {
359 * return drm_mode_config_helper_suspend(dev_get_drvdata(dev));
360 * }
361 *
362 * static int __maybe_unused driver_pm_resume(struct device *dev)
363 * {
364 * drm_mode_config_helper_resume(dev_get_drvdata(dev));
365 *
366 * return 0;
367 * }
368 *
369 * static const struct dev_pm_ops driver_pm_ops = {
370 * SET_SYSTEM_SLEEP_PM_OPS(driver_pm_suspend, driver_pm_resume)
371 * };
372 *
373 * static struct platform_driver driver_driver = {
374 * .driver = {
375 * [...]
376 * .pm = &driver_pm_ops,
377 * },
378 * .probe = driver_probe,
379 * .remove = driver_remove,
380 * .shutdown = driver_shutdown,
381 * };
382 * module_platform_driver(driver_driver);
383 *
384 * Drivers that want to support device unplugging (USB, DT overlay unload) should
385 * use drm_dev_unplug() instead of drm_dev_unregister(). The driver must protect
386 * regions that is accessing device resources to prevent use after they're
387 * released. This is done using drm_dev_enter() and drm_dev_exit(). There is one
388 * shortcoming however, drm_dev_unplug() marks the drm_device as unplugged before
389 * drm_atomic_helper_shutdown() is called. This means that if the disable code
390 * paths are protected, they will not run on regular driver module unload,
391 * possibily leaving the hardware enabled.
392 */
393
394/**
395 * drm_put_dev - Unregister and release a DRM device
396 * @dev: DRM device
397 *
398 * Called at module unload time or when a PCI device is unplugged.
399 *
400 * Cleans up all DRM device, calling drm_lastclose().
401 *
402 * Note: Use of this function is deprecated. It will eventually go away
403 * completely. Please use drm_dev_unregister() and drm_dev_put() explicitly
404 * instead to make sure that the device isn't userspace accessible any more
405 * while teardown is in progress, ensuring that userspace can't access an
406 * inconsistent state.
407 */
408void drm_put_dev(struct drm_device *dev)
409{
410 DRM_DEBUG("\n");
411
412 if (!dev) {
413 DRM_ERROR("cleanup called no dev\n");
414 return;
415 }
416
417 drm_dev_unregister(dev);
418 drm_dev_put(dev);
419}
420EXPORT_SYMBOL(drm_put_dev);
421
422/**
423 * drm_dev_enter - Enter device critical section
424 * @dev: DRM device
425 * @idx: Pointer to index that will be passed to the matching drm_dev_exit()
426 *
427 * This function marks and protects the beginning of a section that should not
428 * be entered after the device has been unplugged. The section end is marked
429 * with drm_dev_exit(). Calls to this function can be nested.
430 *
431 * Returns:
432 * True if it is OK to enter the section, false otherwise.
433 */
434bool drm_dev_enter(struct drm_device *dev, int *idx)
435{
436 *idx = srcu_read_lock(&drm_unplug_srcu);
437
438 if (dev->unplugged) {
439 srcu_read_unlock(&drm_unplug_srcu, *idx);
440 return false;
441 }
442
443 return true;
444}
445EXPORT_SYMBOL(drm_dev_enter);
446
447/**
448 * drm_dev_exit - Exit device critical section
449 * @idx: index returned from drm_dev_enter()
450 *
451 * This function marks the end of a section that should not be entered after
452 * the device has been unplugged.
453 */
454void drm_dev_exit(int idx)
455{
456 srcu_read_unlock(&drm_unplug_srcu, idx);
457}
458EXPORT_SYMBOL(drm_dev_exit);
459
460/**
461 * drm_dev_unplug - unplug a DRM device
462 * @dev: DRM device
463 *
464 * This unplugs a hotpluggable DRM device, which makes it inaccessible to
465 * userspace operations. Entry-points can use drm_dev_enter() and
466 * drm_dev_exit() to protect device resources in a race free manner. This
467 * essentially unregisters the device like drm_dev_unregister(), but can be
468 * called while there are still open users of @dev.
469 */
470void drm_dev_unplug(struct drm_device *dev)
471{
472 /*
473 * After synchronizing any critical read section is guaranteed to see
474 * the new value of ->unplugged, and any critical section which might
475 * still have seen the old value of ->unplugged is guaranteed to have
476 * finished.
477 */
478 dev->unplugged = true;
479 synchronize_srcu(&drm_unplug_srcu);
480
481 drm_dev_unregister(dev);
482}
483EXPORT_SYMBOL(drm_dev_unplug);
484
485/*
486 * DRM internal mount
487 * We want to be able to allocate our own "struct address_space" to control
488 * memory-mappings in VRAM (or stolen RAM, ...). However, core MM does not allow
489 * stand-alone address_space objects, so we need an underlying inode. As there
490 * is no way to allocate an independent inode easily, we need a fake internal
491 * VFS mount-point.
492 *
493 * The drm_fs_inode_new() function allocates a new inode, drm_fs_inode_free()
494 * frees it again. You are allowed to use iget() and iput() to get references to
495 * the inode. But each drm_fs_inode_new() call must be paired with exactly one
496 * drm_fs_inode_free() call (which does not have to be the last iput()).
497 * We use drm_fs_inode_*() to manage our internal VFS mount-point and share it
498 * between multiple inode-users. You could, technically, call
499 * iget() + drm_fs_inode_free() directly after alloc and sometime later do an
500 * iput(), but this way you'd end up with a new vfsmount for each inode.
501 */
502
503static int drm_fs_cnt;
504static struct vfsmount *drm_fs_mnt;
505
506static int drm_fs_init_fs_context(struct fs_context *fc)
507{
508 return init_pseudo(fc, 0x010203ff) ? 0 : -ENOMEM;
509}
510
511static struct file_system_type drm_fs_type = {
512 .name = "drm",
513 .owner = THIS_MODULE,
514 .init_fs_context = drm_fs_init_fs_context,
515 .kill_sb = kill_anon_super,
516};
517
518static struct inode *drm_fs_inode_new(void)
519{
520 struct inode *inode;
521 int r;
522
523 r = simple_pin_fs(&drm_fs_type, &drm_fs_mnt, &drm_fs_cnt);
524 if (r < 0) {
525 DRM_ERROR("Cannot mount pseudo fs: %d\n", r);
526 return ERR_PTR(r);
527 }
528
529 inode = alloc_anon_inode(drm_fs_mnt->mnt_sb);
530 if (IS_ERR(inode))
531 simple_release_fs(&drm_fs_mnt, &drm_fs_cnt);
532
533 return inode;
534}
535
536static void drm_fs_inode_free(struct inode *inode)
537{
538 if (inode) {
539 iput(inode);
540 simple_release_fs(&drm_fs_mnt, &drm_fs_cnt);
541 }
542}
543
544/**
545 * DOC: component helper usage recommendations
546 *
547 * DRM drivers that drive hardware where a logical device consists of a pile of
548 * independent hardware blocks are recommended to use the :ref:`component helper
549 * library<component>`. For consistency and better options for code reuse the
550 * following guidelines apply:
551 *
552 * - The entire device initialization procedure should be run from the
553 * &component_master_ops.master_bind callback, starting with drm_dev_init(),
554 * then binding all components with component_bind_all() and finishing with
555 * drm_dev_register().
556 *
557 * - The opaque pointer passed to all components through component_bind_all()
558 * should point at &struct drm_device of the device instance, not some driver
559 * specific private structure.
560 *
561 * - The component helper fills the niche where further standardization of
562 * interfaces is not practical. When there already is, or will be, a
563 * standardized interface like &drm_bridge or &drm_panel, providing its own
564 * functions to find such components at driver load time, like
565 * drm_of_find_panel_or_bridge(), then the component helper should not be
566 * used.
567 */
568
569static void drm_dev_init_release(struct drm_device *dev, void *res)
570{
571 drm_legacy_ctxbitmap_cleanup(dev);
572 drm_legacy_remove_map_hash(dev);
573 drm_fs_inode_free(dev->anon_inode);
574
575 put_device(dev->dev);
576 /* Prevent use-after-free in drm_managed_release when debugging is
577 * enabled. Slightly awkward, but can't really be helped. */
578 dev->dev = NULL;
579 mutex_destroy(&dev->master_mutex);
580 mutex_destroy(&dev->clientlist_mutex);
581 mutex_destroy(&dev->filelist_mutex);
582 mutex_destroy(&dev->struct_mutex);
583 drm_legacy_destroy_members(dev);
584}
585
586/**
587 * drm_dev_init - Initialise new DRM device
588 * @dev: DRM device
589 * @driver: DRM driver
590 * @parent: Parent device object
591 *
592 * Initialize a new DRM device. No device registration is done.
593 * Call drm_dev_register() to advertice the device to user space and register it
594 * with other core subsystems. This should be done last in the device
595 * initialization sequence to make sure userspace can't access an inconsistent
596 * state.
597 *
598 * The initial ref-count of the object is 1. Use drm_dev_get() and
599 * drm_dev_put() to take and drop further ref-counts.
600 *
601 * It is recommended that drivers embed &struct drm_device into their own device
602 * structure.
603 *
604 * Drivers that do not want to allocate their own device struct
605 * embedding &struct drm_device can call drm_dev_alloc() instead. For drivers
606 * that do embed &struct drm_device it must be placed first in the overall
607 * structure, and the overall structure must be allocated using kmalloc(): The
608 * drm core's release function unconditionally calls kfree() on the @dev pointer
609 * when the final reference is released. To override this behaviour, and so
610 * allow embedding of the drm_device inside the driver's device struct at an
611 * arbitrary offset, you must supply a &drm_driver.release callback and control
612 * the finalization explicitly.
613 *
614 * Note that drivers must call drmm_add_final_kfree() after this function has
615 * completed successfully.
616 *
617 * RETURNS:
618 * 0 on success, or error code on failure.
619 */
620int drm_dev_init(struct drm_device *dev,
621 struct drm_driver *driver,
622 struct device *parent)
623{
624 int ret;
625
626 if (!drm_core_init_complete) {
627 DRM_ERROR("DRM core is not initialized\n");
628 return -ENODEV;
629 }
630
631 if (WARN_ON(!parent))
632 return -EINVAL;
633
634 kref_init(&dev->ref);
635 dev->dev = get_device(parent);
636 dev->driver = driver;
637
638 INIT_LIST_HEAD(&dev->managed.resources);
639 spin_lock_init(&dev->managed.lock);
640
641 /* no per-device feature limits by default */
642 dev->driver_features = ~0u;
643
644 drm_legacy_init_members(dev);
645 INIT_LIST_HEAD(&dev->filelist);
646 INIT_LIST_HEAD(&dev->filelist_internal);
647 INIT_LIST_HEAD(&dev->clientlist);
648 INIT_LIST_HEAD(&dev->vblank_event_list);
649
650 spin_lock_init(&dev->event_lock);
651 mutex_init(&dev->struct_mutex);
652 mutex_init(&dev->filelist_mutex);
653 mutex_init(&dev->clientlist_mutex);
654 mutex_init(&dev->master_mutex);
655
656 ret = drmm_add_action(dev, drm_dev_init_release, NULL);
657 if (ret)
658 return ret;
659
660 dev->anon_inode = drm_fs_inode_new();
661 if (IS_ERR(dev->anon_inode)) {
662 ret = PTR_ERR(dev->anon_inode);
663 DRM_ERROR("Cannot allocate anonymous inode: %d\n", ret);
664 goto err;
665 }
666
667 if (drm_core_check_feature(dev, DRIVER_RENDER)) {
668 ret = drm_minor_alloc(dev, DRM_MINOR_RENDER);
669 if (ret)
670 goto err;
671 }
672
673 ret = drm_minor_alloc(dev, DRM_MINOR_PRIMARY);
674 if (ret)
675 goto err;
676
677 ret = drm_legacy_create_map_hash(dev);
678 if (ret)
679 goto err;
680
681 drm_legacy_ctxbitmap_init(dev);
682
683 if (drm_core_check_feature(dev, DRIVER_GEM)) {
684 ret = drm_gem_init(dev);
685 if (ret) {
686 DRM_ERROR("Cannot initialize graphics execution manager (GEM)\n");
687 goto err;
688 }
689 }
690
691 ret = drm_dev_set_unique(dev, dev_name(parent));
692 if (ret)
693 goto err;
694
695 return 0;
696
697err:
698 drm_managed_release(dev);
699
700 return ret;
701}
702EXPORT_SYMBOL(drm_dev_init);
703
704static void devm_drm_dev_init_release(void *data)
705{
706 drm_dev_put(data);
707}
708
709/**
710 * devm_drm_dev_init - Resource managed drm_dev_init()
711 * @parent: Parent device object
712 * @dev: DRM device
713 * @driver: DRM driver
714 *
715 * Managed drm_dev_init(). The DRM device initialized with this function is
716 * automatically put on driver detach using drm_dev_put().
717 *
718 * Note that drivers must call drmm_add_final_kfree() after this function has
719 * completed successfully.
720 *
721 * RETURNS:
722 * 0 on success, or error code on failure.
723 */
724int devm_drm_dev_init(struct device *parent,
725 struct drm_device *dev,
726 struct drm_driver *driver)
727{
728 int ret;
729
730 ret = drm_dev_init(dev, driver, parent);
731 if (ret)
732 return ret;
733
734 ret = devm_add_action(parent, devm_drm_dev_init_release, dev);
735 if (ret)
736 devm_drm_dev_init_release(dev);
737
738 return ret;
739}
740EXPORT_SYMBOL(devm_drm_dev_init);
741
742void *__devm_drm_dev_alloc(struct device *parent, struct drm_driver *driver,
743 size_t size, size_t offset)
744{
745 void *container;
746 struct drm_device *drm;
747 int ret;
748
749 container = kzalloc(size, GFP_KERNEL);
750 if (!container)
751 return ERR_PTR(-ENOMEM);
752
753 drm = container + offset;
754 ret = devm_drm_dev_init(parent, drm, driver);
755 if (ret) {
756 kfree(container);
757 return ERR_PTR(ret);
758 }
759 drmm_add_final_kfree(drm, container);
760
761 return container;
762}
763EXPORT_SYMBOL(__devm_drm_dev_alloc);
764
765/**
766 * drm_dev_alloc - Allocate new DRM device
767 * @driver: DRM driver to allocate device for
768 * @parent: Parent device object
769 *
770 * Allocate and initialize a new DRM device. No device registration is done.
771 * Call drm_dev_register() to advertice the device to user space and register it
772 * with other core subsystems. This should be done last in the device
773 * initialization sequence to make sure userspace can't access an inconsistent
774 * state.
775 *
776 * The initial ref-count of the object is 1. Use drm_dev_get() and
777 * drm_dev_put() to take and drop further ref-counts.
778 *
779 * Note that for purely virtual devices @parent can be NULL.
780 *
781 * Drivers that wish to subclass or embed &struct drm_device into their
782 * own struct should look at using drm_dev_init() instead.
783 *
784 * RETURNS:
785 * Pointer to new DRM device, or ERR_PTR on failure.
786 */
787struct drm_device *drm_dev_alloc(struct drm_driver *driver,
788 struct device *parent)
789{
790 struct drm_device *dev;
791 int ret;
792
793 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
794 if (!dev)
795 return ERR_PTR(-ENOMEM);
796
797 ret = drm_dev_init(dev, driver, parent);
798 if (ret) {
799 kfree(dev);
800 return ERR_PTR(ret);
801 }
802
803 drmm_add_final_kfree(dev, dev);
804
805 return dev;
806}
807EXPORT_SYMBOL(drm_dev_alloc);
808
809static void drm_dev_release(struct kref *ref)
810{
811 struct drm_device *dev = container_of(ref, struct drm_device, ref);
812
813 if (dev->driver->release)
814 dev->driver->release(dev);
815
816 drm_managed_release(dev);
817
818 kfree(dev->managed.final_kfree);
819}
820
821/**
822 * drm_dev_get - Take reference of a DRM device
823 * @dev: device to take reference of or NULL
824 *
825 * This increases the ref-count of @dev by one. You *must* already own a
826 * reference when calling this. Use drm_dev_put() to drop this reference
827 * again.
828 *
829 * This function never fails. However, this function does not provide *any*
830 * guarantee whether the device is alive or running. It only provides a
831 * reference to the object and the memory associated with it.
832 */
833void drm_dev_get(struct drm_device *dev)
834{
835 if (dev)
836 kref_get(&dev->ref);
837}
838EXPORT_SYMBOL(drm_dev_get);
839
840/**
841 * drm_dev_put - Drop reference of a DRM device
842 * @dev: device to drop reference of or NULL
843 *
844 * This decreases the ref-count of @dev by one. The device is destroyed if the
845 * ref-count drops to zero.
846 */
847void drm_dev_put(struct drm_device *dev)
848{
849 if (dev)
850 kref_put(&dev->ref, drm_dev_release);
851}
852EXPORT_SYMBOL(drm_dev_put);
853
854static int create_compat_control_link(struct drm_device *dev)
855{
856 struct drm_minor *minor;
857 char *name;
858 int ret;
859
860 if (!drm_core_check_feature(dev, DRIVER_MODESET))
861 return 0;
862
863 minor = *drm_minor_get_slot(dev, DRM_MINOR_PRIMARY);
864 if (!minor)
865 return 0;
866
867 /*
868 * Some existing userspace out there uses the existing of the controlD*
869 * sysfs files to figure out whether it's a modeset driver. It only does
870 * readdir, hence a symlink is sufficient (and the least confusing
871 * option). Otherwise controlD* is entirely unused.
872 *
873 * Old controlD chardev have been allocated in the range
874 * 64-127.
875 */
876 name = kasprintf(GFP_KERNEL, "controlD%d", minor->index + 64);
877 if (!name)
878 return -ENOMEM;
879
880 ret = sysfs_create_link(minor->kdev->kobj.parent,
881 &minor->kdev->kobj,
882 name);
883
884 kfree(name);
885
886 return ret;
887}
888
889static void remove_compat_control_link(struct drm_device *dev)
890{
891 struct drm_minor *minor;
892 char *name;
893
894 if (!drm_core_check_feature(dev, DRIVER_MODESET))
895 return;
896
897 minor = *drm_minor_get_slot(dev, DRM_MINOR_PRIMARY);
898 if (!minor)
899 return;
900
901 name = kasprintf(GFP_KERNEL, "controlD%d", minor->index + 64);
902 if (!name)
903 return;
904
905 sysfs_remove_link(minor->kdev->kobj.parent, name);
906
907 kfree(name);
908}
909
910/**
911 * drm_dev_register - Register DRM device
912 * @dev: Device to register
913 * @flags: Flags passed to the driver's .load() function
914 *
915 * Register the DRM device @dev with the system, advertise device to user-space
916 * and start normal device operation. @dev must be initialized via drm_dev_init()
917 * previously.
918 *
919 * Never call this twice on any device!
920 *
921 * NOTE: To ensure backward compatibility with existing drivers method this
922 * function calls the &drm_driver.load method after registering the device
923 * nodes, creating race conditions. Usage of the &drm_driver.load methods is
924 * therefore deprecated, drivers must perform all initialization before calling
925 * drm_dev_register().
926 *
927 * RETURNS:
928 * 0 on success, negative error code on failure.
929 */
930int drm_dev_register(struct drm_device *dev, unsigned long flags)
931{
932 struct drm_driver *driver = dev->driver;
933 int ret;
934
935 if (!driver->load)
936 drm_mode_config_validate(dev);
937
938 WARN_ON(!dev->managed.final_kfree);
939
940 if (drm_dev_needs_global_mutex(dev))
941 mutex_lock(&drm_global_mutex);
942
943 ret = drm_minor_register(dev, DRM_MINOR_RENDER);
944 if (ret)
945 goto err_minors;
946
947 ret = drm_minor_register(dev, DRM_MINOR_PRIMARY);
948 if (ret)
949 goto err_minors;
950
951 ret = create_compat_control_link(dev);
952 if (ret)
953 goto err_minors;
954
955 dev->registered = true;
956
957 if (dev->driver->load) {
958 ret = dev->driver->load(dev, flags);
959 if (ret)
960 goto err_minors;
961 }
962
963 if (drm_core_check_feature(dev, DRIVER_MODESET))
964 drm_modeset_register_all(dev);
965
966 ret = 0;
967
968 DRM_INFO("Initialized %s %d.%d.%d %s for %s on minor %d\n",
969 driver->name, driver->major, driver->minor,
970 driver->patchlevel, driver->date,
971 dev->dev ? dev_name(dev->dev) : "virtual device",
972 dev->primary->index);
973
974 goto out_unlock;
975
976err_minors:
977 remove_compat_control_link(dev);
978 drm_minor_unregister(dev, DRM_MINOR_PRIMARY);
979 drm_minor_unregister(dev, DRM_MINOR_RENDER);
980out_unlock:
981 if (drm_dev_needs_global_mutex(dev))
982 mutex_unlock(&drm_global_mutex);
983 return ret;
984}
985EXPORT_SYMBOL(drm_dev_register);
986
987/**
988 * drm_dev_unregister - Unregister DRM device
989 * @dev: Device to unregister
990 *
991 * Unregister the DRM device from the system. This does the reverse of
992 * drm_dev_register() but does not deallocate the device. The caller must call
993 * drm_dev_put() to drop their final reference.
994 *
995 * A special form of unregistering for hotpluggable devices is drm_dev_unplug(),
996 * which can be called while there are still open users of @dev.
997 *
998 * This should be called first in the device teardown code to make sure
999 * userspace can't access the device instance any more.
1000 */
1001void drm_dev_unregister(struct drm_device *dev)
1002{
1003 if (drm_core_check_feature(dev, DRIVER_LEGACY))
1004 drm_lastclose(dev);
1005
1006 dev->registered = false;
1007
1008 drm_client_dev_unregister(dev);
1009
1010 if (drm_core_check_feature(dev, DRIVER_MODESET))
1011 drm_modeset_unregister_all(dev);
1012
1013 if (dev->driver->unload)
1014 dev->driver->unload(dev);
1015
1016 if (dev->agp)
1017 drm_pci_agp_destroy(dev);
1018
1019 drm_legacy_rmmaps(dev);
1020
1021 remove_compat_control_link(dev);
1022 drm_minor_unregister(dev, DRM_MINOR_PRIMARY);
1023 drm_minor_unregister(dev, DRM_MINOR_RENDER);
1024}
1025EXPORT_SYMBOL(drm_dev_unregister);
1026
1027/**
1028 * drm_dev_set_unique - Set the unique name of a DRM device
1029 * @dev: device of which to set the unique name
1030 * @name: unique name
1031 *
1032 * Sets the unique name of a DRM device using the specified string. This is
1033 * already done by drm_dev_init(), drivers should only override the default
1034 * unique name for backwards compatibility reasons.
1035 *
1036 * Return: 0 on success or a negative error code on failure.
1037 */
1038int drm_dev_set_unique(struct drm_device *dev, const char *name)
1039{
1040 drmm_kfree(dev, dev->unique);
1041 dev->unique = drmm_kstrdup(dev, name, GFP_KERNEL);
1042
1043 return dev->unique ? 0 : -ENOMEM;
1044}
1045EXPORT_SYMBOL(drm_dev_set_unique);
1046
1047/*
1048 * DRM Core
1049 * The DRM core module initializes all global DRM objects and makes them
1050 * available to drivers. Once setup, drivers can probe their respective
1051 * devices.
1052 * Currently, core management includes:
1053 * - The "DRM-Global" key/value database
1054 * - Global ID management for connectors
1055 * - DRM major number allocation
1056 * - DRM minor management
1057 * - DRM sysfs class
1058 * - DRM debugfs root
1059 *
1060 * Furthermore, the DRM core provides dynamic char-dev lookups. For each
1061 * interface registered on a DRM device, you can request minor numbers from DRM
1062 * core. DRM core takes care of major-number management and char-dev
1063 * registration. A stub ->open() callback forwards any open() requests to the
1064 * registered minor.
1065 */
1066
1067static int drm_stub_open(struct inode *inode, struct file *filp)
1068{
1069 const struct file_operations *new_fops;
1070 struct drm_minor *minor;
1071 int err;
1072
1073 DRM_DEBUG("\n");
1074
1075 minor = drm_minor_acquire(iminor(inode));
1076 if (IS_ERR(minor))
1077 return PTR_ERR(minor);
1078
1079 new_fops = fops_get(minor->dev->driver->fops);
1080 if (!new_fops) {
1081 err = -ENODEV;
1082 goto out;
1083 }
1084
1085 replace_fops(filp, new_fops);
1086 if (filp->f_op->open)
1087 err = filp->f_op->open(inode, filp);
1088 else
1089 err = 0;
1090
1091out:
1092 drm_minor_release(minor);
1093
1094 return err;
1095}
1096
1097static const struct file_operations drm_stub_fops = {
1098 .owner = THIS_MODULE,
1099 .open = drm_stub_open,
1100 .llseek = noop_llseek,
1101};
1102
1103static void drm_core_exit(void)
1104{
1105 unregister_chrdev(DRM_MAJOR, "drm");
1106 debugfs_remove(drm_debugfs_root);
1107 drm_sysfs_destroy();
1108 idr_destroy(&drm_minors_idr);
1109 drm_connector_ida_destroy();
1110}
1111
1112static int __init drm_core_init(void)
1113{
1114 int ret;
1115
1116 drm_connector_ida_init();
1117 idr_init(&drm_minors_idr);
1118
1119 ret = drm_sysfs_init();
1120 if (ret < 0) {
1121 DRM_ERROR("Cannot create DRM class: %d\n", ret);
1122 goto error;
1123 }
1124
1125 drm_debugfs_root = debugfs_create_dir("dri", NULL);
1126
1127 ret = register_chrdev(DRM_MAJOR, "drm", &drm_stub_fops);
1128 if (ret < 0)
1129 goto error;
1130
1131 drm_core_init_complete = true;
1132
1133 DRM_DEBUG("Initialized\n");
1134 return 0;
1135
1136error:
1137 drm_core_exit();
1138 return ret;
1139}
1140
1141module_init(drm_core_init);
1142module_exit(drm_core_exit);