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_mode_object.h>
43 #include <drm/drm_print.h>
44
45 #include "drm_crtc_internal.h"
46 #include "drm_internal.h"
47 #include "drm_legacy.h"
48
49 /*
50 * drm_debug: Enable debug output.
51 * Bitmask of DRM_UT_x. See include/drm/drm_print.h for details.
52 */
53 unsigned int drm_debug = 0;
54 EXPORT_SYMBOL(drm_debug);
55
56 MODULE_AUTHOR("Gareth Hughes, Leif Delgass, José Fonseca, Jon Smirl");
57 MODULE_DESCRIPTION("DRM shared core routines");
58 MODULE_LICENSE("GPL and additional rights");
59 MODULE_PARM_DESC(debug, "Enable debug output, where each bit enables a debug category.\n"
60 "\t\tBit 0 (0x01) will enable CORE messages (drm core code)\n"
61 "\t\tBit 1 (0x02) will enable DRIVER messages (drm controller code)\n"
62 "\t\tBit 2 (0x04) will enable KMS messages (modesetting code)\n"
63 "\t\tBit 3 (0x08) will enable PRIME messages (prime code)\n"
64 "\t\tBit 4 (0x10) will enable ATOMIC messages (atomic code)\n"
65 "\t\tBit 5 (0x20) will enable VBL messages (vblank code)\n"
66 "\t\tBit 7 (0x80) will enable LEASE messages (leasing code)\n"
67 "\t\tBit 8 (0x100) will enable DP messages (displayport code)");
68 module_param_named(debug, drm_debug, int, 0600);
69
70 static DEFINE_SPINLOCK(drm_minor_lock);
71 static struct idr drm_minors_idr;
72
73 /*
74 * If the drm core fails to init for whatever reason,
75 * we should prevent any drivers from registering with it.
76 * It's best to check this at drm_dev_init(), as some drivers
77 * prefer to embed struct drm_device into their own device
78 * structure and call drm_dev_init() themselves.
79 */
80 static bool drm_core_init_complete = false;
81
82 static struct dentry *drm_debugfs_root;
83
84 DEFINE_STATIC_SRCU(drm_unplug_srcu);
85
86 /*
87 * DRM Minors
88 * A DRM device can provide several char-dev interfaces on the DRM-Major. Each
89 * of them is represented by a drm_minor object. Depending on the capabilities
90 * of the device-driver, different interfaces are registered.
91 *
92 * Minors can be accessed via dev->$minor_name. This pointer is either
93 * NULL or a valid drm_minor pointer and stays valid as long as the device is
94 * valid. This means, DRM minors have the same life-time as the underlying
95 * device. However, this doesn't mean that the minor is active. Minors are
96 * registered and unregistered dynamically according to device-state.
97 */
98
99 static struct drm_minor **drm_minor_get_slot(struct drm_device *dev,
100 unsigned int type)
101 {
102 switch (type) {
103 case DRM_MINOR_PRIMARY:
104 return &dev->primary;
105 case DRM_MINOR_RENDER:
106 return &dev->render;
107 default:
108 BUG();
109 }
110 }
111
112 static int drm_minor_alloc(struct drm_device *dev, unsigned int type)
113 {
114 struct drm_minor *minor;
115 unsigned long flags;
116 int r;
117
118 minor = kzalloc(sizeof(*minor), GFP_KERNEL);
119 if (!minor)
120 return -ENOMEM;
121
122 minor->type = type;
123 minor->dev = dev;
124
125 idr_preload(GFP_KERNEL);
126 spin_lock_irqsave(&drm_minor_lock, flags);
127 r = idr_alloc(&drm_minors_idr,
128 NULL,
129 64 * type,
130 64 * (type + 1),
131 GFP_NOWAIT);
132 spin_unlock_irqrestore(&drm_minor_lock, flags);
133 idr_preload_end();
134
135 if (r < 0)
136 goto err_free;
137
138 minor->index = r;
139
140 minor->kdev = drm_sysfs_minor_alloc(minor);
141 if (IS_ERR(minor->kdev)) {
142 r = PTR_ERR(minor->kdev);
143 goto err_index;
144 }
145
146 *drm_minor_get_slot(dev, type) = minor;
147 return 0;
148
149 err_index:
150 spin_lock_irqsave(&drm_minor_lock, flags);
151 idr_remove(&drm_minors_idr, minor->index);
152 spin_unlock_irqrestore(&drm_minor_lock, flags);
153 err_free:
154 kfree(minor);
155 return r;
156 }
157
158 static void drm_minor_free(struct drm_device *dev, unsigned int type)
159 {
160 struct drm_minor **slot, *minor;
161 unsigned long flags;
162
163 slot = drm_minor_get_slot(dev, type);
164 minor = *slot;
165 if (!minor)
166 return;
167
168 put_device(minor->kdev);
169
170 spin_lock_irqsave(&drm_minor_lock, flags);
171 idr_remove(&drm_minors_idr, minor->index);
172 spin_unlock_irqrestore(&drm_minor_lock, flags);
173
174 kfree(minor);
175 *slot = NULL;
176 }
177
178 static int drm_minor_register(struct drm_device *dev, unsigned int type)
179 {
180 struct drm_minor *minor;
181 unsigned long flags;
182 int ret;
183
184 DRM_DEBUG("\n");
185
186 minor = *drm_minor_get_slot(dev, type);
187 if (!minor)
188 return 0;
189
190 ret = drm_debugfs_init(minor, minor->index, drm_debugfs_root);
191 if (ret) {
192 DRM_ERROR("DRM: Failed to initialize /sys/kernel/debug/dri.\n");
193 goto err_debugfs;
194 }
195
196 ret = device_add(minor->kdev);
197 if (ret)
198 goto err_debugfs;
199
200 /* replace NULL with @minor so lookups will succeed from now on */
201 spin_lock_irqsave(&drm_minor_lock, flags);
202 idr_replace(&drm_minors_idr, minor, minor->index);
203 spin_unlock_irqrestore(&drm_minor_lock, flags);
204
205 DRM_DEBUG("new minor registered %d\n", minor->index);
206 return 0;
207
208 err_debugfs:
209 drm_debugfs_cleanup(minor);
210 return ret;
211 }
212
213 static void drm_minor_unregister(struct drm_device *dev, unsigned int type)
214 {
215 struct drm_minor *minor;
216 unsigned long flags;
217
218 minor = *drm_minor_get_slot(dev, type);
219 if (!minor || !device_is_registered(minor->kdev))
220 return;
221
222 /* replace @minor with NULL so lookups will fail from now on */
223 spin_lock_irqsave(&drm_minor_lock, flags);
224 idr_replace(&drm_minors_idr, NULL, minor->index);
225 spin_unlock_irqrestore(&drm_minor_lock, flags);
226
227 device_del(minor->kdev);
228 dev_set_drvdata(minor->kdev, NULL); /* safety belt */
229 drm_debugfs_cleanup(minor);
230 }
231
232 /*
233 * Looks up the given minor-ID and returns the respective DRM-minor object. The
234 * refence-count of the underlying device is increased so you must release this
235 * object with drm_minor_release().
236 *
237 * As long as you hold this minor, it is guaranteed that the object and the
238 * minor->dev pointer will stay valid! However, the device may get unplugged and
239 * unregistered while you hold the minor.
240 */
241 struct drm_minor *drm_minor_acquire(unsigned int minor_id)
242 {
243 struct drm_minor *minor;
244 unsigned long flags;
245
246 spin_lock_irqsave(&drm_minor_lock, flags);
247 minor = idr_find(&drm_minors_idr, minor_id);
248 if (minor)
249 drm_dev_get(minor->dev);
250 spin_unlock_irqrestore(&drm_minor_lock, flags);
251
252 if (!minor) {
253 return ERR_PTR(-ENODEV);
254 } else if (drm_dev_is_unplugged(minor->dev)) {
255 drm_dev_put(minor->dev);
256 return ERR_PTR(-ENODEV);
257 }
258
259 return minor;
260 }
261
262 void drm_minor_release(struct drm_minor *minor)
263 {
264 drm_dev_put(minor->dev);
265 }
266
267 /**
268 * DOC: driver instance overview
269 *
270 * A device instance for a drm driver is represented by &struct drm_device. This
271 * is initialized with drm_dev_init(), usually from bus-specific ->probe()
272 * callbacks implemented by the driver. The driver then needs to initialize all
273 * the various subsystems for the drm device like memory management, vblank
274 * handling, modesetting support and intial output configuration plus obviously
275 * initialize all the corresponding hardware bits. Finally when everything is up
276 * and running and ready for userspace the device instance can be published
277 * using drm_dev_register().
278 *
279 * There is also deprecated support for initalizing device instances using
280 * bus-specific helpers and the &drm_driver.load callback. But due to
281 * backwards-compatibility needs the device instance have to be published too
282 * early, which requires unpretty global locking to make safe and is therefore
283 * only support for existing drivers not yet converted to the new scheme.
284 *
285 * When cleaning up a device instance everything needs to be done in reverse:
286 * First unpublish the device instance with drm_dev_unregister(). Then clean up
287 * any other resources allocated at device initialization and drop the driver's
288 * reference to &drm_device using drm_dev_put().
289 *
290 * Note that the lifetime rules for &drm_device instance has still a lot of
291 * historical baggage. Hence use the reference counting provided by
292 * drm_dev_get() and drm_dev_put() only carefully.
293 *
294 * Display driver example
295 * ~~~~~~~~~~~~~~~~~~~~~~
296 *
297 * The following example shows a typical structure of a DRM display driver.
298 * The example focus on the probe() function and the other functions that is
299 * almost always present and serves as a demonstration of devm_drm_dev_init()
300 * usage with its accompanying drm_driver->release callback.
301 *
302 * .. code-block:: c
303 *
304 * struct driver_device {
305 * struct drm_device drm;
306 * void *userspace_facing;
307 * struct clk *pclk;
308 * };
309 *
310 * static void driver_drm_release(struct drm_device *drm)
311 * {
312 * struct driver_device *priv = container_of(...);
313 *
314 * drm_mode_config_cleanup(drm);
315 * drm_dev_fini(drm);
316 * kfree(priv->userspace_facing);
317 * kfree(priv);
318 * }
319 *
320 * static struct drm_driver driver_drm_driver = {
321 * [...]
322 * .release = driver_drm_release,
323 * };
324 *
325 * static int driver_probe(struct platform_device *pdev)
326 * {
327 * struct driver_device *priv;
328 * struct drm_device *drm;
329 * int ret;
330 *
331 * // devm_kzalloc() can't be used here because the drm_device '
332 * // lifetime can exceed the device lifetime if driver unbind
333 * // happens when userspace still has open file descriptors.
334 * priv = kzalloc(sizeof(*priv), GFP_KERNEL);
335 * if (!priv)
336 * return -ENOMEM;
337 *
338 * drm = &priv->drm;
339 *
340 * ret = devm_drm_dev_init(&pdev->dev, drm, &driver_drm_driver);
341 * if (ret) {
342 * kfree(drm);
343 * return ret;
344 * }
345 *
346 * drm_mode_config_init(drm);
347 *
348 * priv->userspace_facing = kzalloc(..., GFP_KERNEL);
349 * if (!priv->userspace_facing)
350 * return -ENOMEM;
351 *
352 * priv->pclk = devm_clk_get(dev, "PCLK");
353 * if (IS_ERR(priv->pclk))
354 * return PTR_ERR(priv->pclk);
355 *
356 * // Further setup, display pipeline etc
357 *
358 * platform_set_drvdata(pdev, drm);
359 *
360 * drm_mode_config_reset(drm);
361 *
362 * ret = drm_dev_register(drm);
363 * if (ret)
364 * return ret;
365 *
366 * drm_fbdev_generic_setup(drm, 32);
367 *
368 * return 0;
369 * }
370 *
371 * // This function is called before the devm_ resources are released
372 * static int driver_remove(struct platform_device *pdev)
373 * {
374 * struct drm_device *drm = platform_get_drvdata(pdev);
375 *
376 * drm_dev_unregister(drm);
377 * drm_atomic_helper_shutdown(drm)
378 *
379 * return 0;
380 * }
381 *
382 * // This function is called on kernel restart and shutdown
383 * static void driver_shutdown(struct platform_device *pdev)
384 * {
385 * drm_atomic_helper_shutdown(platform_get_drvdata(pdev));
386 * }
387 *
388 * static int __maybe_unused driver_pm_suspend(struct device *dev)
389 * {
390 * return drm_mode_config_helper_suspend(dev_get_drvdata(dev));
391 * }
392 *
393 * static int __maybe_unused driver_pm_resume(struct device *dev)
394 * {
395 * drm_mode_config_helper_resume(dev_get_drvdata(dev));
396 *
397 * return 0;
398 * }
399 *
400 * static const struct dev_pm_ops driver_pm_ops = {
401 * SET_SYSTEM_SLEEP_PM_OPS(driver_pm_suspend, driver_pm_resume)
402 * };
403 *
404 * static struct platform_driver driver_driver = {
405 * .driver = {
406 * [...]
407 * .pm = &driver_pm_ops,
408 * },
409 * .probe = driver_probe,
410 * .remove = driver_remove,
411 * .shutdown = driver_shutdown,
412 * };
413 * module_platform_driver(driver_driver);
414 *
415 * Drivers that want to support device unplugging (USB, DT overlay unload) should
416 * use drm_dev_unplug() instead of drm_dev_unregister(). The driver must protect
417 * regions that is accessing device resources to prevent use after they're
418 * released. This is done using drm_dev_enter() and drm_dev_exit(). There is one
419 * shortcoming however, drm_dev_unplug() marks the drm_device as unplugged before
420 * drm_atomic_helper_shutdown() is called. This means that if the disable code
421 * paths are protected, they will not run on regular driver module unload,
422 * possibily leaving the hardware enabled.
423 */
424
425 /**
426 * drm_put_dev - Unregister and release a DRM device
427 * @dev: DRM device
428 *
429 * Called at module unload time or when a PCI device is unplugged.
430 *
431 * Cleans up all DRM device, calling drm_lastclose().
432 *
433 * Note: Use of this function is deprecated. It will eventually go away
434 * completely. Please use drm_dev_unregister() and drm_dev_put() explicitly
435 * instead to make sure that the device isn't userspace accessible any more
436 * while teardown is in progress, ensuring that userspace can't access an
437 * inconsistent state.
438 */
439 void drm_put_dev(struct drm_device *dev)
440 {
441 DRM_DEBUG("\n");
442
443 if (!dev) {
444 DRM_ERROR("cleanup called no dev\n");
445 return;
446 }
447
448 drm_dev_unregister(dev);
449 drm_dev_put(dev);
450 }
451 EXPORT_SYMBOL(drm_put_dev);
452
453 /**
454 * drm_dev_enter - Enter device critical section
455 * @dev: DRM device
456 * @idx: Pointer to index that will be passed to the matching drm_dev_exit()
457 *
458 * This function marks and protects the beginning of a section that should not
459 * be entered after the device has been unplugged. The section end is marked
460 * with drm_dev_exit(). Calls to this function can be nested.
461 *
462 * Returns:
463 * True if it is OK to enter the section, false otherwise.
464 */
465 bool drm_dev_enter(struct drm_device *dev, int *idx)
466 {
467 *idx = srcu_read_lock(&drm_unplug_srcu);
468
469 if (dev->unplugged) {
470 srcu_read_unlock(&drm_unplug_srcu, *idx);
471 return false;
472 }
473
474 return true;
475 }
476 EXPORT_SYMBOL(drm_dev_enter);
477
478 /**
479 * drm_dev_exit - Exit device critical section
480 * @idx: index returned from drm_dev_enter()
481 *
482 * This function marks the end of a section that should not be entered after
483 * the device has been unplugged.
484 */
485 void drm_dev_exit(int idx)
486 {
487 srcu_read_unlock(&drm_unplug_srcu, idx);
488 }
489 EXPORT_SYMBOL(drm_dev_exit);
490
491 /**
492 * drm_dev_unplug - unplug a DRM device
493 * @dev: DRM device
494 *
495 * This unplugs a hotpluggable DRM device, which makes it inaccessible to
496 * userspace operations. Entry-points can use drm_dev_enter() and
497 * drm_dev_exit() to protect device resources in a race free manner. This
498 * essentially unregisters the device like drm_dev_unregister(), but can be
499 * called while there are still open users of @dev.
500 */
501 void drm_dev_unplug(struct drm_device *dev)
502 {
503 /*
504 * After synchronizing any critical read section is guaranteed to see
505 * the new value of ->unplugged, and any critical section which might
506 * still have seen the old value of ->unplugged is guaranteed to have
507 * finished.
508 */
509 dev->unplugged = true;
510 synchronize_srcu(&drm_unplug_srcu);
511
512 drm_dev_unregister(dev);
513 }
514 EXPORT_SYMBOL(drm_dev_unplug);
515
516 /*
517 * DRM internal mount
518 * We want to be able to allocate our own "struct address_space" to control
519 * memory-mappings in VRAM (or stolen RAM, ...). However, core MM does not allow
520 * stand-alone address_space objects, so we need an underlying inode. As there
521 * is no way to allocate an independent inode easily, we need a fake internal
522 * VFS mount-point.
523 *
524 * The drm_fs_inode_new() function allocates a new inode, drm_fs_inode_free()
525 * frees it again. You are allowed to use iget() and iput() to get references to
526 * the inode. But each drm_fs_inode_new() call must be paired with exactly one
527 * drm_fs_inode_free() call (which does not have to be the last iput()).
528 * We use drm_fs_inode_*() to manage our internal VFS mount-point and share it
529 * between multiple inode-users. You could, technically, call
530 * iget() + drm_fs_inode_free() directly after alloc and sometime later do an
531 * iput(), but this way you'd end up with a new vfsmount for each inode.
532 */
533
534 static int drm_fs_cnt;
535 static struct vfsmount *drm_fs_mnt;
536
537 static int drm_fs_init_fs_context(struct fs_context *fc)
538 {
539 return init_pseudo(fc, 0x010203ff) ? 0 : -ENOMEM;
540 }
541
542 static struct file_system_type drm_fs_type = {
543 .name = "drm",
544 .owner = THIS_MODULE,
545 .init_fs_context = drm_fs_init_fs_context,
546 .kill_sb = kill_anon_super,
547 };
548
549 static struct inode *drm_fs_inode_new(void)
550 {
551 struct inode *inode;
552 int r;
553
554 r = simple_pin_fs(&drm_fs_type, &drm_fs_mnt, &drm_fs_cnt);
555 if (r < 0) {
556 DRM_ERROR("Cannot mount pseudo fs: %d\n", r);
557 return ERR_PTR(r);
558 }
559
560 inode = alloc_anon_inode(drm_fs_mnt->mnt_sb);
561 if (IS_ERR(inode))
562 simple_release_fs(&drm_fs_mnt, &drm_fs_cnt);
563
564 return inode;
565 }
566
567 static void drm_fs_inode_free(struct inode *inode)
568 {
569 if (inode) {
570 iput(inode);
571 simple_release_fs(&drm_fs_mnt, &drm_fs_cnt);
572 }
573 }
574
575 /**
576 * DOC: component helper usage recommendations
577 *
578 * DRM drivers that drive hardware where a logical device consists of a pile of
579 * independent hardware blocks are recommended to use the :ref:`component helper
580 * library<component>`. For consistency and better options for code reuse the
581 * following guidelines apply:
582 *
583 * - The entire device initialization procedure should be run from the
584 * &component_master_ops.master_bind callback, starting with drm_dev_init(),
585 * then binding all components with component_bind_all() and finishing with
586 * drm_dev_register().
587 *
588 * - The opaque pointer passed to all components through component_bind_all()
589 * should point at &struct drm_device of the device instance, not some driver
590 * specific private structure.
591 *
592 * - The component helper fills the niche where further standardization of
593 * interfaces is not practical. When there already is, or will be, a
594 * standardized interface like &drm_bridge or &drm_panel, providing its own
595 * functions to find such components at driver load time, like
596 * drm_of_find_panel_or_bridge(), then the component helper should not be
597 * used.
598 */
599
600 /**
601 * drm_dev_init - Initialise new DRM device
602 * @dev: DRM device
603 * @driver: DRM driver
604 * @parent: Parent device object
605 *
606 * Initialize a new DRM device. No device registration is done.
607 * Call drm_dev_register() to advertice the device to user space and register it
608 * with other core subsystems. This should be done last in the device
609 * initialization sequence to make sure userspace can't access an inconsistent
610 * state.
611 *
612 * The initial ref-count of the object is 1. Use drm_dev_get() and
613 * drm_dev_put() to take and drop further ref-counts.
614 *
615 * It is recommended that drivers embed &struct drm_device into their own device
616 * structure.
617 *
618 * Drivers that do not want to allocate their own device struct
619 * embedding &struct drm_device can call drm_dev_alloc() instead. For drivers
620 * that do embed &struct drm_device it must be placed first in the overall
621 * structure, and the overall structure must be allocated using kmalloc(): The
622 * drm core's release function unconditionally calls kfree() on the @dev pointer
623 * when the final reference is released. To override this behaviour, and so
624 * allow embedding of the drm_device inside the driver's device struct at an
625 * arbitrary offset, you must supply a &drm_driver.release callback and control
626 * the finalization explicitly.
627 *
628 * RETURNS:
629 * 0 on success, or error code on failure.
630 */
631 int drm_dev_init(struct drm_device *dev,
632 struct drm_driver *driver,
633 struct device *parent)
634 {
635 int ret;
636
637 if (!drm_core_init_complete) {
638 DRM_ERROR("DRM core is not initialized\n");
639 return -ENODEV;
640 }
641
642 BUG_ON(!parent);
643
644 kref_init(&dev->ref);
645 dev->dev = get_device(parent);
646 dev->driver = driver;
647
648 /* no per-device feature limits by default */
649 dev->driver_features = ~0u;
650
651 drm_legacy_init_members(dev);
652 INIT_LIST_HEAD(&dev->filelist);
653 INIT_LIST_HEAD(&dev->filelist_internal);
654 INIT_LIST_HEAD(&dev->clientlist);
655 INIT_LIST_HEAD(&dev->vblank_event_list);
656
657 spin_lock_init(&dev->event_lock);
658 mutex_init(&dev->struct_mutex);
659 mutex_init(&dev->filelist_mutex);
660 mutex_init(&dev->clientlist_mutex);
661 mutex_init(&dev->master_mutex);
662
663 dev->anon_inode = drm_fs_inode_new();
664 if (IS_ERR(dev->anon_inode)) {
665 ret = PTR_ERR(dev->anon_inode);
666 DRM_ERROR("Cannot allocate anonymous inode: %d\n", ret);
667 goto err_free;
668 }
669
670 if (drm_core_check_feature(dev, DRIVER_RENDER)) {
671 ret = drm_minor_alloc(dev, DRM_MINOR_RENDER);
672 if (ret)
673 goto err_minors;
674 }
675
676 ret = drm_minor_alloc(dev, DRM_MINOR_PRIMARY);
677 if (ret)
678 goto err_minors;
679
680 ret = drm_legacy_create_map_hash(dev);
681 if (ret)
682 goto err_minors;
683
684 drm_legacy_ctxbitmap_init(dev);
685
686 if (drm_core_check_feature(dev, DRIVER_GEM)) {
687 ret = drm_gem_init(dev);
688 if (ret) {
689 DRM_ERROR("Cannot initialize graphics execution manager (GEM)\n");
690 goto err_ctxbitmap;
691 }
692 }
693
694 ret = drm_dev_set_unique(dev, dev_name(parent));
695 if (ret)
696 goto err_setunique;
697
698 return 0;
699
700 err_setunique:
701 if (drm_core_check_feature(dev, DRIVER_GEM))
702 drm_gem_destroy(dev);
703 err_ctxbitmap:
704 drm_legacy_ctxbitmap_cleanup(dev);
705 drm_legacy_remove_map_hash(dev);
706 err_minors:
707 drm_minor_free(dev, DRM_MINOR_PRIMARY);
708 drm_minor_free(dev, DRM_MINOR_RENDER);
709 drm_fs_inode_free(dev->anon_inode);
710 err_free:
711 put_device(dev->dev);
712 mutex_destroy(&dev->master_mutex);
713 mutex_destroy(&dev->clientlist_mutex);
714 mutex_destroy(&dev->filelist_mutex);
715 mutex_destroy(&dev->struct_mutex);
716 drm_legacy_destroy_members(dev);
717 return ret;
718 }
719 EXPORT_SYMBOL(drm_dev_init);
720
721 static void devm_drm_dev_init_release(void *data)
722 {
723 drm_dev_put(data);
724 }
725
726 /**
727 * devm_drm_dev_init - Resource managed drm_dev_init()
728 * @parent: Parent device object
729 * @dev: DRM device
730 * @driver: DRM driver
731 *
732 * Managed drm_dev_init(). The DRM device initialized with this function is
733 * automatically put on driver detach using drm_dev_put(). You must supply a
734 * &drm_driver.release callback to control the finalization explicitly.
735 *
736 * RETURNS:
737 * 0 on success, or error code on failure.
738 */
739 int devm_drm_dev_init(struct device *parent,
740 struct drm_device *dev,
741 struct drm_driver *driver)
742 {
743 int ret;
744
745 if (WARN_ON(!parent || !driver->release))
746 return -EINVAL;
747
748 ret = drm_dev_init(dev, driver, parent);
749 if (ret)
750 return ret;
751
752 ret = devm_add_action(parent, devm_drm_dev_init_release, dev);
753 if (ret)
754 devm_drm_dev_init_release(dev);
755
756 return ret;
757 }
758 EXPORT_SYMBOL(devm_drm_dev_init);
759
760 /**
761 * drm_dev_fini - Finalize a dead DRM device
762 * @dev: DRM device
763 *
764 * Finalize a dead DRM device. This is the converse to drm_dev_init() and
765 * frees up all data allocated by it. All driver private data should be
766 * finalized first. Note that this function does not free the @dev, that is
767 * left to the caller.
768 *
769 * The ref-count of @dev must be zero, and drm_dev_fini() should only be called
770 * from a &drm_driver.release callback.
771 */
772 void drm_dev_fini(struct drm_device *dev)
773 {
774 drm_vblank_cleanup(dev);
775
776 if (drm_core_check_feature(dev, DRIVER_GEM))
777 drm_gem_destroy(dev);
778
779 drm_legacy_ctxbitmap_cleanup(dev);
780 drm_legacy_remove_map_hash(dev);
781 drm_fs_inode_free(dev->anon_inode);
782
783 drm_minor_free(dev, DRM_MINOR_PRIMARY);
784 drm_minor_free(dev, DRM_MINOR_RENDER);
785
786 put_device(dev->dev);
787
788 mutex_destroy(&dev->master_mutex);
789 mutex_destroy(&dev->clientlist_mutex);
790 mutex_destroy(&dev->filelist_mutex);
791 mutex_destroy(&dev->struct_mutex);
792 drm_legacy_destroy_members(dev);
793 kfree(dev->unique);
794 }
795 EXPORT_SYMBOL(drm_dev_fini);
796
797 /**
798 * drm_dev_alloc - Allocate new DRM device
799 * @driver: DRM driver to allocate device for
800 * @parent: Parent device object
801 *
802 * Allocate and initialize a new DRM device. No device registration is done.
803 * Call drm_dev_register() to advertice the device to user space and register it
804 * with other core subsystems. This should be done last in the device
805 * initialization sequence to make sure userspace can't access an inconsistent
806 * state.
807 *
808 * The initial ref-count of the object is 1. Use drm_dev_get() and
809 * drm_dev_put() to take and drop further ref-counts.
810 *
811 * Note that for purely virtual devices @parent can be NULL.
812 *
813 * Drivers that wish to subclass or embed &struct drm_device into their
814 * own struct should look at using drm_dev_init() instead.
815 *
816 * RETURNS:
817 * Pointer to new DRM device, or ERR_PTR on failure.
818 */
819 struct drm_device *drm_dev_alloc(struct drm_driver *driver,
820 struct device *parent)
821 {
822 struct drm_device *dev;
823 int ret;
824
825 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
826 if (!dev)
827 return ERR_PTR(-ENOMEM);
828
829 ret = drm_dev_init(dev, driver, parent);
830 if (ret) {
831 kfree(dev);
832 return ERR_PTR(ret);
833 }
834
835 return dev;
836 }
837 EXPORT_SYMBOL(drm_dev_alloc);
838
839 static void drm_dev_release(struct kref *ref)
840 {
841 struct drm_device *dev = container_of(ref, struct drm_device, ref);
842
843 if (dev->driver->release) {
844 dev->driver->release(dev);
845 } else {
846 drm_dev_fini(dev);
847 kfree(dev);
848 }
849 }
850
851 /**
852 * drm_dev_get - Take reference of a DRM device
853 * @dev: device to take reference of or NULL
854 *
855 * This increases the ref-count of @dev by one. You *must* already own a
856 * reference when calling this. Use drm_dev_put() to drop this reference
857 * again.
858 *
859 * This function never fails. However, this function does not provide *any*
860 * guarantee whether the device is alive or running. It only provides a
861 * reference to the object and the memory associated with it.
862 */
863 void drm_dev_get(struct drm_device *dev)
864 {
865 if (dev)
866 kref_get(&dev->ref);
867 }
868 EXPORT_SYMBOL(drm_dev_get);
869
870 /**
871 * drm_dev_put - Drop reference of a DRM device
872 * @dev: device to drop reference of or NULL
873 *
874 * This decreases the ref-count of @dev by one. The device is destroyed if the
875 * ref-count drops to zero.
876 */
877 void drm_dev_put(struct drm_device *dev)
878 {
879 if (dev)
880 kref_put(&dev->ref, drm_dev_release);
881 }
882 EXPORT_SYMBOL(drm_dev_put);
883
884 static int create_compat_control_link(struct drm_device *dev)
885 {
886 struct drm_minor *minor;
887 char *name;
888 int ret;
889
890 if (!drm_core_check_feature(dev, DRIVER_MODESET))
891 return 0;
892
893 minor = *drm_minor_get_slot(dev, DRM_MINOR_PRIMARY);
894 if (!minor)
895 return 0;
896
897 /*
898 * Some existing userspace out there uses the existing of the controlD*
899 * sysfs files to figure out whether it's a modeset driver. It only does
900 * readdir, hence a symlink is sufficient (and the least confusing
901 * option). Otherwise controlD* is entirely unused.
902 *
903 * Old controlD chardev have been allocated in the range
904 * 64-127.
905 */
906 name = kasprintf(GFP_KERNEL, "controlD%d", minor->index + 64);
907 if (!name)
908 return -ENOMEM;
909
910 ret = sysfs_create_link(minor->kdev->kobj.parent,
911 &minor->kdev->kobj,
912 name);
913
914 kfree(name);
915
916 return ret;
917 }
918
919 static void remove_compat_control_link(struct drm_device *dev)
920 {
921 struct drm_minor *minor;
922 char *name;
923
924 if (!drm_core_check_feature(dev, DRIVER_MODESET))
925 return;
926
927 minor = *drm_minor_get_slot(dev, DRM_MINOR_PRIMARY);
928 if (!minor)
929 return;
930
931 name = kasprintf(GFP_KERNEL, "controlD%d", minor->index + 64);
932 if (!name)
933 return;
934
935 sysfs_remove_link(minor->kdev->kobj.parent, name);
936
937 kfree(name);
938 }
939
940 /**
941 * drm_dev_register - Register DRM device
942 * @dev: Device to register
943 * @flags: Flags passed to the driver's .load() function
944 *
945 * Register the DRM device @dev with the system, advertise device to user-space
946 * and start normal device operation. @dev must be initialized via drm_dev_init()
947 * previously.
948 *
949 * Never call this twice on any device!
950 *
951 * NOTE: To ensure backward compatibility with existing drivers method this
952 * function calls the &drm_driver.load method after registering the device
953 * nodes, creating race conditions. Usage of the &drm_driver.load methods is
954 * therefore deprecated, drivers must perform all initialization before calling
955 * drm_dev_register().
956 *
957 * RETURNS:
958 * 0 on success, negative error code on failure.
959 */
960 int drm_dev_register(struct drm_device *dev, unsigned long flags)
961 {
962 struct drm_driver *driver = dev->driver;
963 int ret;
964
965 mutex_lock(&drm_global_mutex);
966
967 ret = drm_minor_register(dev, DRM_MINOR_RENDER);
968 if (ret)
969 goto err_minors;
970
971 ret = drm_minor_register(dev, DRM_MINOR_PRIMARY);
972 if (ret)
973 goto err_minors;
974
975 ret = create_compat_control_link(dev);
976 if (ret)
977 goto err_minors;
978
979 dev->registered = true;
980
981 if (dev->driver->load) {
982 ret = dev->driver->load(dev, flags);
983 if (ret)
984 goto err_minors;
985 }
986
987 if (drm_core_check_feature(dev, DRIVER_MODESET))
988 drm_modeset_register_all(dev);
989
990 ret = 0;
991
992 DRM_INFO("Initialized %s %d.%d.%d %s for %s on minor %d\n",
993 driver->name, driver->major, driver->minor,
994 driver->patchlevel, driver->date,
995 dev->dev ? dev_name(dev->dev) : "virtual device",
996 dev->primary->index);
997
998 goto out_unlock;
999
1000 err_minors:
1001 remove_compat_control_link(dev);
1002 drm_minor_unregister(dev, DRM_MINOR_PRIMARY);
1003 drm_minor_unregister(dev, DRM_MINOR_RENDER);
1004 out_unlock:
1005 mutex_unlock(&drm_global_mutex);
1006 return ret;
1007 }
1008 EXPORT_SYMBOL(drm_dev_register);
1009
1010 /**
1011 * drm_dev_unregister - Unregister DRM device
1012 * @dev: Device to unregister
1013 *
1014 * Unregister the DRM device from the system. This does the reverse of
1015 * drm_dev_register() but does not deallocate the device. The caller must call
1016 * drm_dev_put() to drop their final reference.
1017 *
1018 * A special form of unregistering for hotpluggable devices is drm_dev_unplug(),
1019 * which can be called while there are still open users of @dev.
1020 *
1021 * This should be called first in the device teardown code to make sure
1022 * userspace can't access the device instance any more.
1023 */
1024 void drm_dev_unregister(struct drm_device *dev)
1025 {
1026 if (drm_core_check_feature(dev, DRIVER_LEGACY))
1027 drm_lastclose(dev);
1028
1029 dev->registered = false;
1030
1031 drm_client_dev_unregister(dev);
1032
1033 if (drm_core_check_feature(dev, DRIVER_MODESET))
1034 drm_modeset_unregister_all(dev);
1035
1036 if (dev->driver->unload)
1037 dev->driver->unload(dev);
1038
1039 if (dev->agp)
1040 drm_pci_agp_destroy(dev);
1041
1042 drm_legacy_rmmaps(dev);
1043
1044 remove_compat_control_link(dev);
1045 drm_minor_unregister(dev, DRM_MINOR_PRIMARY);
1046 drm_minor_unregister(dev, DRM_MINOR_RENDER);
1047 }
1048 EXPORT_SYMBOL(drm_dev_unregister);
1049
1050 /**
1051 * drm_dev_set_unique - Set the unique name of a DRM device
1052 * @dev: device of which to set the unique name
1053 * @name: unique name
1054 *
1055 * Sets the unique name of a DRM device using the specified string. This is
1056 * already done by drm_dev_init(), drivers should only override the default
1057 * unique name for backwards compatibility reasons.
1058 *
1059 * Return: 0 on success or a negative error code on failure.
1060 */
1061 int drm_dev_set_unique(struct drm_device *dev, const char *name)
1062 {
1063 kfree(dev->unique);
1064 dev->unique = kstrdup(name, GFP_KERNEL);
1065
1066 return dev->unique ? 0 : -ENOMEM;
1067 }
1068 EXPORT_SYMBOL(drm_dev_set_unique);
1069
1070 /*
1071 * DRM Core
1072 * The DRM core module initializes all global DRM objects and makes them
1073 * available to drivers. Once setup, drivers can probe their respective
1074 * devices.
1075 * Currently, core management includes:
1076 * - The "DRM-Global" key/value database
1077 * - Global ID management for connectors
1078 * - DRM major number allocation
1079 * - DRM minor management
1080 * - DRM sysfs class
1081 * - DRM debugfs root
1082 *
1083 * Furthermore, the DRM core provides dynamic char-dev lookups. For each
1084 * interface registered on a DRM device, you can request minor numbers from DRM
1085 * core. DRM core takes care of major-number management and char-dev
1086 * registration. A stub ->open() callback forwards any open() requests to the
1087 * registered minor.
1088 */
1089
1090 static int drm_stub_open(struct inode *inode, struct file *filp)
1091 {
1092 const struct file_operations *new_fops;
1093 struct drm_minor *minor;
1094 int err;
1095
1096 DRM_DEBUG("\n");
1097
1098 mutex_lock(&drm_global_mutex);
1099 minor = drm_minor_acquire(iminor(inode));
1100 if (IS_ERR(minor)) {
1101 err = PTR_ERR(minor);
1102 goto out_unlock;
1103 }
1104
1105 new_fops = fops_get(minor->dev->driver->fops);
1106 if (!new_fops) {
1107 err = -ENODEV;
1108 goto out_release;
1109 }
1110
1111 replace_fops(filp, new_fops);
1112 if (filp->f_op->open)
1113 err = filp->f_op->open(inode, filp);
1114 else
1115 err = 0;
1116
1117 out_release:
1118 drm_minor_release(minor);
1119 out_unlock:
1120 mutex_unlock(&drm_global_mutex);
1121 return err;
1122 }
1123
1124 static const struct file_operations drm_stub_fops = {
1125 .owner = THIS_MODULE,
1126 .open = drm_stub_open,
1127 .llseek = noop_llseek,
1128 };
1129
1130 static void drm_core_exit(void)
1131 {
1132 unregister_chrdev(DRM_MAJOR, "drm");
1133 debugfs_remove(drm_debugfs_root);
1134 drm_sysfs_destroy();
1135 idr_destroy(&drm_minors_idr);
1136 drm_connector_ida_destroy();
1137 }
1138
1139 static int __init drm_core_init(void)
1140 {
1141 int ret;
1142
1143 drm_connector_ida_init();
1144 idr_init(&drm_minors_idr);
1145
1146 ret = drm_sysfs_init();
1147 if (ret < 0) {
1148 DRM_ERROR("Cannot create DRM class: %d\n", ret);
1149 goto error;
1150 }
1151
1152 drm_debugfs_root = debugfs_create_dir("dri", NULL);
1153
1154 ret = register_chrdev(DRM_MAJOR, "drm", &drm_stub_fops);
1155 if (ret < 0)
1156 goto error;
1157
1158 drm_core_init_complete = true;
1159
1160 DRM_DEBUG("Initialized\n");
1161 return 0;
1162
1163 error:
1164 drm_core_exit();
1165 return ret;
1166 }
1167
1168 module_init(drm_core_init);
1169 module_exit(drm_core_exit);