2 * Created: Fri Jan 19 10:48:35 2001 by faith@acm.org
4 * Copyright 2001 VA Linux Systems, Inc., Sunnyvale, California.
7 * Author Rickard E. (Rik) Faith <faith@valinux.com>
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:
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
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.
29 #include <linux/debugfs.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>
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>
46 #include "drm_crtc_internal.h"
47 #include "drm_internal.h"
48 #include "drm_legacy.h"
50 MODULE_AUTHOR("Gareth Hughes, Leif Delgass, José Fonseca, Jon Smirl");
51 MODULE_DESCRIPTION("DRM shared core routines");
52 MODULE_LICENSE("GPL and additional rights");
54 static DEFINE_SPINLOCK(drm_minor_lock
);
55 static struct idr drm_minors_idr
;
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.
64 static bool drm_core_init_complete
= false;
66 static struct dentry
*drm_debugfs_root
;
68 DEFINE_STATIC_SRCU(drm_unplug_srcu
);
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.
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.
83 static struct drm_minor
**drm_minor_get_slot(struct drm_device
*dev
,
87 case DRM_MINOR_PRIMARY
:
89 case DRM_MINOR_RENDER
:
96 static void drm_minor_alloc_release(struct drm_device
*dev
, void *data
)
98 struct drm_minor
*minor
= data
;
101 WARN_ON(dev
!= minor
->dev
);
103 put_device(minor
->kdev
);
105 spin_lock_irqsave(&drm_minor_lock
, flags
);
106 idr_remove(&drm_minors_idr
, minor
->index
);
107 spin_unlock_irqrestore(&drm_minor_lock
, flags
);
110 static int drm_minor_alloc(struct drm_device
*dev
, unsigned int type
)
112 struct drm_minor
*minor
;
116 minor
= drmm_kzalloc(dev
, sizeof(*minor
), GFP_KERNEL
);
123 idr_preload(GFP_KERNEL
);
124 spin_lock_irqsave(&drm_minor_lock
, flags
);
125 r
= idr_alloc(&drm_minors_idr
,
130 spin_unlock_irqrestore(&drm_minor_lock
, flags
);
138 r
= drmm_add_action_or_reset(dev
, drm_minor_alloc_release
, minor
);
142 minor
->kdev
= drm_sysfs_minor_alloc(minor
);
143 if (IS_ERR(minor
->kdev
))
144 return PTR_ERR(minor
->kdev
);
146 *drm_minor_get_slot(dev
, type
) = minor
;
150 static int drm_minor_register(struct drm_device
*dev
, unsigned int type
)
152 struct drm_minor
*minor
;
158 minor
= *drm_minor_get_slot(dev
, type
);
162 ret
= drm_debugfs_init(minor
, minor
->index
, drm_debugfs_root
);
164 DRM_ERROR("DRM: Failed to initialize /sys/kernel/debug/dri.\n");
168 ret
= device_add(minor
->kdev
);
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
);
177 DRM_DEBUG("new minor registered %d\n", minor
->index
);
181 drm_debugfs_cleanup(minor
);
185 static void drm_minor_unregister(struct drm_device
*dev
, unsigned int type
)
187 struct drm_minor
*minor
;
190 minor
= *drm_minor_get_slot(dev
, type
);
191 if (!minor
|| !device_is_registered(minor
->kdev
))
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
);
199 device_del(minor
->kdev
);
200 dev_set_drvdata(minor
->kdev
, NULL
); /* safety belt */
201 drm_debugfs_cleanup(minor
);
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().
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.
213 struct drm_minor
*drm_minor_acquire(unsigned int minor_id
)
215 struct drm_minor
*minor
;
218 spin_lock_irqsave(&drm_minor_lock
, flags
);
219 minor
= idr_find(&drm_minors_idr
, minor_id
);
221 drm_dev_get(minor
->dev
);
222 spin_unlock_irqrestore(&drm_minor_lock
, flags
);
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
);
234 void drm_minor_release(struct drm_minor
*minor
)
236 drm_dev_put(minor
->dev
);
240 * DOC: driver instance overview
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().
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.
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().
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
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().
272 * Display driver example
273 * ~~~~~~~~~~~~~~~~~~~~~~
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().
281 * struct driver_device {
282 * struct drm_device drm;
283 * void *userspace_facing;
287 * static struct drm_driver driver_drm_driver = {
291 * static int driver_probe(struct platform_device *pdev)
293 * struct driver_device *priv;
294 * struct drm_device *drm;
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);
306 * ret = devm_drm_dev_init(&pdev->dev, drm, &driver_drm_driver);
311 * drmm_add_final_kfree(drm, priv);
313 * ret = drmm_mode_config_init(drm);
317 * priv->userspace_facing = drmm_kzalloc(..., GFP_KERNEL);
318 * if (!priv->userspace_facing)
321 * priv->pclk = devm_clk_get(dev, "PCLK");
322 * if (IS_ERR(priv->pclk))
323 * return PTR_ERR(priv->pclk);
325 * // Further setup, display pipeline etc
327 * platform_set_drvdata(pdev, drm);
329 * drm_mode_config_reset(drm);
331 * ret = drm_dev_register(drm);
335 * drm_fbdev_generic_setup(drm, 32);
340 * // This function is called before the devm_ resources are released
341 * static int driver_remove(struct platform_device *pdev)
343 * struct drm_device *drm = platform_get_drvdata(pdev);
345 * drm_dev_unregister(drm);
346 * drm_atomic_helper_shutdown(drm)
351 * // This function is called on kernel restart and shutdown
352 * static void driver_shutdown(struct platform_device *pdev)
354 * drm_atomic_helper_shutdown(platform_get_drvdata(pdev));
357 * static int __maybe_unused driver_pm_suspend(struct device *dev)
359 * return drm_mode_config_helper_suspend(dev_get_drvdata(dev));
362 * static int __maybe_unused driver_pm_resume(struct device *dev)
364 * drm_mode_config_helper_resume(dev_get_drvdata(dev));
369 * static const struct dev_pm_ops driver_pm_ops = {
370 * SET_SYSTEM_SLEEP_PM_OPS(driver_pm_suspend, driver_pm_resume)
373 * static struct platform_driver driver_driver = {
376 * .pm = &driver_pm_ops,
378 * .probe = driver_probe,
379 * .remove = driver_remove,
380 * .shutdown = driver_shutdown,
382 * module_platform_driver(driver_driver);
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.
395 * drm_put_dev - Unregister and release a DRM device
398 * Called at module unload time or when a PCI device is unplugged.
400 * Cleans up all DRM device, calling drm_lastclose().
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.
408 void drm_put_dev(struct drm_device
*dev
)
413 DRM_ERROR("cleanup called no dev\n");
417 drm_dev_unregister(dev
);
420 EXPORT_SYMBOL(drm_put_dev
);
423 * drm_dev_enter - Enter device critical section
425 * @idx: Pointer to index that will be passed to the matching drm_dev_exit()
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.
432 * True if it is OK to enter the section, false otherwise.
434 bool drm_dev_enter(struct drm_device
*dev
, int *idx
)
436 *idx
= srcu_read_lock(&drm_unplug_srcu
);
438 if (dev
->unplugged
) {
439 srcu_read_unlock(&drm_unplug_srcu
, *idx
);
445 EXPORT_SYMBOL(drm_dev_enter
);
448 * drm_dev_exit - Exit device critical section
449 * @idx: index returned from drm_dev_enter()
451 * This function marks the end of a section that should not be entered after
452 * the device has been unplugged.
454 void drm_dev_exit(int idx
)
456 srcu_read_unlock(&drm_unplug_srcu
, idx
);
458 EXPORT_SYMBOL(drm_dev_exit
);
461 * drm_dev_unplug - unplug a DRM device
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.
470 void drm_dev_unplug(struct drm_device
*dev
)
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
478 dev
->unplugged
= true;
479 synchronize_srcu(&drm_unplug_srcu
);
481 drm_dev_unregister(dev
);
483 EXPORT_SYMBOL(drm_dev_unplug
);
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
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.
503 static int drm_fs_cnt
;
504 static struct vfsmount
*drm_fs_mnt
;
506 static int drm_fs_init_fs_context(struct fs_context
*fc
)
508 return init_pseudo(fc
, 0x010203ff) ? 0 : -ENOMEM
;
511 static struct file_system_type drm_fs_type
= {
513 .owner
= THIS_MODULE
,
514 .init_fs_context
= drm_fs_init_fs_context
,
515 .kill_sb
= kill_anon_super
,
518 static struct inode
*drm_fs_inode_new(void)
523 r
= simple_pin_fs(&drm_fs_type
, &drm_fs_mnt
, &drm_fs_cnt
);
525 DRM_ERROR("Cannot mount pseudo fs: %d\n", r
);
529 inode
= alloc_anon_inode(drm_fs_mnt
->mnt_sb
);
531 simple_release_fs(&drm_fs_mnt
, &drm_fs_cnt
);
536 static void drm_fs_inode_free(struct inode
*inode
)
540 simple_release_fs(&drm_fs_mnt
, &drm_fs_cnt
);
545 * DOC: component helper usage recommendations
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:
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().
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.
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
569 static void drm_dev_init_release(struct drm_device
*dev
, void *res
)
571 drm_legacy_ctxbitmap_cleanup(dev
);
572 drm_legacy_remove_map_hash(dev
);
573 drm_fs_inode_free(dev
->anon_inode
);
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. */
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
);
587 * drm_dev_init - Initialise new DRM device
589 * @driver: DRM driver
590 * @parent: Parent device object
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
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.
601 * It is recommended that drivers embed &struct drm_device into their own device
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.
614 * Note that drivers must call drmm_add_final_kfree() after this function has
615 * completed successfully.
618 * 0 on success, or error code on failure.
620 int drm_dev_init(struct drm_device
*dev
,
621 struct drm_driver
*driver
,
622 struct device
*parent
)
626 if (!drm_core_init_complete
) {
627 DRM_ERROR("DRM core is not initialized\n");
631 if (WARN_ON(!parent
))
634 kref_init(&dev
->ref
);
635 dev
->dev
= get_device(parent
);
636 dev
->driver
= driver
;
638 INIT_LIST_HEAD(&dev
->managed
.resources
);
639 spin_lock_init(&dev
->managed
.lock
);
641 /* no per-device feature limits by default */
642 dev
->driver_features
= ~0u;
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
);
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
);
656 ret
= drmm_add_action(dev
, drm_dev_init_release
, NULL
);
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
);
667 if (drm_core_check_feature(dev
, DRIVER_RENDER
)) {
668 ret
= drm_minor_alloc(dev
, DRM_MINOR_RENDER
);
673 ret
= drm_minor_alloc(dev
, DRM_MINOR_PRIMARY
);
677 ret
= drm_legacy_create_map_hash(dev
);
681 drm_legacy_ctxbitmap_init(dev
);
683 if (drm_core_check_feature(dev
, DRIVER_GEM
)) {
684 ret
= drm_gem_init(dev
);
686 DRM_ERROR("Cannot initialize graphics execution manager (GEM)\n");
691 ret
= drm_dev_set_unique(dev
, dev_name(parent
));
698 drm_managed_release(dev
);
702 EXPORT_SYMBOL(drm_dev_init
);
704 static void devm_drm_dev_init_release(void *data
)
710 * devm_drm_dev_init - Resource managed drm_dev_init()
711 * @parent: Parent device object
713 * @driver: DRM driver
715 * Managed drm_dev_init(). The DRM device initialized with this function is
716 * automatically put on driver detach using drm_dev_put().
718 * Note that drivers must call drmm_add_final_kfree() after this function has
719 * completed successfully.
722 * 0 on success, or error code on failure.
724 int devm_drm_dev_init(struct device
*parent
,
725 struct drm_device
*dev
,
726 struct drm_driver
*driver
)
730 ret
= drm_dev_init(dev
, driver
, parent
);
734 ret
= devm_add_action(parent
, devm_drm_dev_init_release
, dev
);
736 devm_drm_dev_init_release(dev
);
740 EXPORT_SYMBOL(devm_drm_dev_init
);
742 void *__devm_drm_dev_alloc(struct device
*parent
, struct drm_driver
*driver
,
743 size_t size
, size_t offset
)
746 struct drm_device
*drm
;
749 container
= kzalloc(size
, GFP_KERNEL
);
751 return ERR_PTR(-ENOMEM
);
753 drm
= container
+ offset
;
754 ret
= devm_drm_dev_init(parent
, drm
, driver
);
759 drmm_add_final_kfree(drm
, container
);
763 EXPORT_SYMBOL(__devm_drm_dev_alloc
);
766 * drm_dev_alloc - Allocate new DRM device
767 * @driver: DRM driver to allocate device for
768 * @parent: Parent device object
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
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.
779 * Note that for purely virtual devices @parent can be NULL.
781 * Drivers that wish to subclass or embed &struct drm_device into their
782 * own struct should look at using drm_dev_init() instead.
785 * Pointer to new DRM device, or ERR_PTR on failure.
787 struct drm_device
*drm_dev_alloc(struct drm_driver
*driver
,
788 struct device
*parent
)
790 struct drm_device
*dev
;
793 dev
= kzalloc(sizeof(*dev
), GFP_KERNEL
);
795 return ERR_PTR(-ENOMEM
);
797 ret
= drm_dev_init(dev
, driver
, parent
);
803 drmm_add_final_kfree(dev
, dev
);
807 EXPORT_SYMBOL(drm_dev_alloc
);
809 static void drm_dev_release(struct kref
*ref
)
811 struct drm_device
*dev
= container_of(ref
, struct drm_device
, ref
);
813 if (dev
->driver
->release
)
814 dev
->driver
->release(dev
);
816 drm_managed_release(dev
);
818 kfree(dev
->managed
.final_kfree
);
822 * drm_dev_get - Take reference of a DRM device
823 * @dev: device to take reference of or NULL
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
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.
833 void drm_dev_get(struct drm_device
*dev
)
838 EXPORT_SYMBOL(drm_dev_get
);
841 * drm_dev_put - Drop reference of a DRM device
842 * @dev: device to drop reference of or NULL
844 * This decreases the ref-count of @dev by one. The device is destroyed if the
845 * ref-count drops to zero.
847 void drm_dev_put(struct drm_device
*dev
)
850 kref_put(&dev
->ref
, drm_dev_release
);
852 EXPORT_SYMBOL(drm_dev_put
);
854 static int create_compat_control_link(struct drm_device
*dev
)
856 struct drm_minor
*minor
;
860 if (!drm_core_check_feature(dev
, DRIVER_MODESET
))
863 minor
= *drm_minor_get_slot(dev
, DRM_MINOR_PRIMARY
);
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.
873 * Old controlD chardev have been allocated in the range
876 name
= kasprintf(GFP_KERNEL
, "controlD%d", minor
->index
+ 64);
880 ret
= sysfs_create_link(minor
->kdev
->kobj
.parent
,
889 static void remove_compat_control_link(struct drm_device
*dev
)
891 struct drm_minor
*minor
;
894 if (!drm_core_check_feature(dev
, DRIVER_MODESET
))
897 minor
= *drm_minor_get_slot(dev
, DRM_MINOR_PRIMARY
);
901 name
= kasprintf(GFP_KERNEL
, "controlD%d", minor
->index
+ 64);
905 sysfs_remove_link(minor
->kdev
->kobj
.parent
, name
);
911 * drm_dev_register - Register DRM device
912 * @dev: Device to register
913 * @flags: Flags passed to the driver's .load() function
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()
919 * Never call this twice on any device!
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().
928 * 0 on success, negative error code on failure.
930 int drm_dev_register(struct drm_device
*dev
, unsigned long flags
)
932 struct drm_driver
*driver
= dev
->driver
;
936 drm_mode_config_validate(dev
);
938 WARN_ON(!dev
->managed
.final_kfree
);
940 if (drm_dev_needs_global_mutex(dev
))
941 mutex_lock(&drm_global_mutex
);
943 ret
= drm_minor_register(dev
, DRM_MINOR_RENDER
);
947 ret
= drm_minor_register(dev
, DRM_MINOR_PRIMARY
);
951 ret
= create_compat_control_link(dev
);
955 dev
->registered
= true;
957 if (dev
->driver
->load
) {
958 ret
= dev
->driver
->load(dev
, flags
);
963 if (drm_core_check_feature(dev
, DRIVER_MODESET
))
964 drm_modeset_register_all(dev
);
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
);
977 remove_compat_control_link(dev
);
978 drm_minor_unregister(dev
, DRM_MINOR_PRIMARY
);
979 drm_minor_unregister(dev
, DRM_MINOR_RENDER
);
981 if (drm_dev_needs_global_mutex(dev
))
982 mutex_unlock(&drm_global_mutex
);
985 EXPORT_SYMBOL(drm_dev_register
);
988 * drm_dev_unregister - Unregister DRM device
989 * @dev: Device to unregister
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.
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.
998 * This should be called first in the device teardown code to make sure
999 * userspace can't access the device instance any more.
1001 void drm_dev_unregister(struct drm_device
*dev
)
1003 if (drm_core_check_feature(dev
, DRIVER_LEGACY
))
1006 dev
->registered
= false;
1008 drm_client_dev_unregister(dev
);
1010 if (drm_core_check_feature(dev
, DRIVER_MODESET
))
1011 drm_modeset_unregister_all(dev
);
1013 if (dev
->driver
->unload
)
1014 dev
->driver
->unload(dev
);
1017 drm_pci_agp_destroy(dev
);
1019 drm_legacy_rmmaps(dev
);
1021 remove_compat_control_link(dev
);
1022 drm_minor_unregister(dev
, DRM_MINOR_PRIMARY
);
1023 drm_minor_unregister(dev
, DRM_MINOR_RENDER
);
1025 EXPORT_SYMBOL(drm_dev_unregister
);
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
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.
1036 * Return: 0 on success or a negative error code on failure.
1038 int drm_dev_set_unique(struct drm_device
*dev
, const char *name
)
1040 drmm_kfree(dev
, dev
->unique
);
1041 dev
->unique
= drmm_kstrdup(dev
, name
, GFP_KERNEL
);
1043 return dev
->unique
? 0 : -ENOMEM
;
1045 EXPORT_SYMBOL(drm_dev_set_unique
);
1049 * The DRM core module initializes all global DRM objects and makes them
1050 * available to drivers. Once setup, drivers can probe their respective
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
1058 * - DRM debugfs root
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
1067 static int drm_stub_open(struct inode
*inode
, struct file
*filp
)
1069 const struct file_operations
*new_fops
;
1070 struct drm_minor
*minor
;
1075 minor
= drm_minor_acquire(iminor(inode
));
1077 return PTR_ERR(minor
);
1079 new_fops
= fops_get(minor
->dev
->driver
->fops
);
1085 replace_fops(filp
, new_fops
);
1086 if (filp
->f_op
->open
)
1087 err
= filp
->f_op
->open(inode
, filp
);
1092 drm_minor_release(minor
);
1097 static const struct file_operations drm_stub_fops
= {
1098 .owner
= THIS_MODULE
,
1099 .open
= drm_stub_open
,
1100 .llseek
= noop_llseek
,
1103 static void drm_core_exit(void)
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();
1112 static int __init
drm_core_init(void)
1116 drm_connector_ida_init();
1117 idr_init(&drm_minors_idr
);
1119 ret
= drm_sysfs_init();
1121 DRM_ERROR("Cannot create DRM class: %d\n", ret
);
1125 drm_debugfs_root
= debugfs_create_dir("dri", NULL
);
1127 ret
= register_chrdev(DRM_MAJOR
, "drm", &drm_stub_fops
);
1131 drm_core_init_complete
= true;
1133 DRM_DEBUG("Initialized\n");
1141 module_init(drm_core_init
);
1142 module_exit(drm_core_exit
);