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_accel.h>
39 #include <drm/drm_cache.h>
40 #include <drm/drm_client.h>
41 #include <drm/drm_color_mgmt.h>
42 #include <drm/drm_drv.h>
43 #include <drm/drm_file.h>
44 #include <drm/drm_managed.h>
45 #include <drm/drm_mode_object.h>
46 #include <drm/drm_print.h>
47 #include <drm/drm_privacy_screen_machine.h>
49 #include "drm_crtc_internal.h"
50 #include "drm_internal.h"
51 #include "drm_legacy.h"
53 MODULE_AUTHOR("Gareth Hughes, Leif Delgass, José Fonseca, Jon Smirl");
54 MODULE_DESCRIPTION("DRM shared core routines");
55 MODULE_LICENSE("GPL and additional rights");
57 static DEFINE_SPINLOCK(drm_minor_lock);
58 static struct idr drm_minors_idr;
61 * If the drm core fails to init for whatever reason,
62 * we should prevent any drivers from registering with it.
63 * It's best to check this at drm_dev_init(), as some drivers
64 * prefer to embed struct drm_device into their own device
65 * structure and call drm_dev_init() themselves.
67 static bool drm_core_init_complete;
69 static struct dentry *drm_debugfs_root;
71 DEFINE_STATIC_SRCU(drm_unplug_srcu);
75 * A DRM device can provide several char-dev interfaces on the DRM-Major. Each
76 * of them is represented by a drm_minor object. Depending on the capabilities
77 * of the device-driver, different interfaces are registered.
79 * Minors can be accessed via dev->$minor_name. This pointer is either
80 * NULL or a valid drm_minor pointer and stays valid as long as the device is
81 * valid. This means, DRM minors have the same life-time as the underlying
82 * device. However, this doesn't mean that the minor is active. Minors are
83 * registered and unregistered dynamically according to device-state.
86 static struct drm_minor **drm_minor_get_slot(struct drm_device *dev,
90 case DRM_MINOR_PRIMARY:
92 case DRM_MINOR_RENDER:
101 static void drm_minor_alloc_release(struct drm_device *dev, void *data)
103 struct drm_minor *minor = data;
106 WARN_ON(dev != minor->dev);
108 put_device(minor->kdev);
110 if (minor->type == DRM_MINOR_ACCEL) {
111 accel_minor_remove(minor->index);
113 spin_lock_irqsave(&drm_minor_lock, flags);
114 idr_remove(&drm_minors_idr, minor->index);
115 spin_unlock_irqrestore(&drm_minor_lock, flags);
119 static int drm_minor_alloc(struct drm_device *dev, unsigned int type)
121 struct drm_minor *minor;
125 minor = drmm_kzalloc(dev, sizeof(*minor), GFP_KERNEL);
132 idr_preload(GFP_KERNEL);
133 if (type == DRM_MINOR_ACCEL) {
134 r = accel_minor_alloc();
136 spin_lock_irqsave(&drm_minor_lock, flags);
137 r = idr_alloc(&drm_minors_idr,
142 spin_unlock_irqrestore(&drm_minor_lock, flags);
151 r = drmm_add_action_or_reset(dev, drm_minor_alloc_release, minor);
155 minor->kdev = drm_sysfs_minor_alloc(minor);
156 if (IS_ERR(minor->kdev))
157 return PTR_ERR(minor->kdev);
159 *drm_minor_get_slot(dev, type) = minor;
163 static int drm_minor_register(struct drm_device *dev, unsigned int type)
165 struct drm_minor *minor;
171 minor = *drm_minor_get_slot(dev, type);
175 if (minor->type == DRM_MINOR_ACCEL) {
176 accel_debugfs_init(minor, minor->index);
178 ret = drm_debugfs_init(minor, minor->index, drm_debugfs_root);
180 DRM_ERROR("DRM: Failed to initialize /sys/kernel/debug/dri.\n");
185 ret = device_add(minor->kdev);
189 /* replace NULL with @minor so lookups will succeed from now on */
190 if (minor->type == DRM_MINOR_ACCEL) {
191 accel_minor_replace(minor, minor->index);
193 spin_lock_irqsave(&drm_minor_lock, flags);
194 idr_replace(&drm_minors_idr, minor, minor->index);
195 spin_unlock_irqrestore(&drm_minor_lock, flags);
198 DRM_DEBUG("new minor registered %d\n", minor->index);
202 drm_debugfs_cleanup(minor);
206 static void drm_minor_unregister(struct drm_device *dev, unsigned int type)
208 struct drm_minor *minor;
211 minor = *drm_minor_get_slot(dev, type);
212 if (!minor || !device_is_registered(minor->kdev))
215 /* replace @minor with NULL so lookups will fail from now on */
216 if (minor->type == DRM_MINOR_ACCEL) {
217 accel_minor_replace(NULL, minor->index);
219 spin_lock_irqsave(&drm_minor_lock, flags);
220 idr_replace(&drm_minors_idr, NULL, minor->index);
221 spin_unlock_irqrestore(&drm_minor_lock, flags);
224 device_del(minor->kdev);
225 dev_set_drvdata(minor->kdev, NULL); /* safety belt */
226 drm_debugfs_cleanup(minor);
230 * Looks up the given minor-ID and returns the respective DRM-minor object. The
231 * refence-count of the underlying device is increased so you must release this
232 * object with drm_minor_release().
234 * As long as you hold this minor, it is guaranteed that the object and the
235 * minor->dev pointer will stay valid! However, the device may get unplugged and
236 * unregistered while you hold the minor.
238 struct drm_minor *drm_minor_acquire(unsigned int minor_id)
240 struct drm_minor *minor;
243 spin_lock_irqsave(&drm_minor_lock, flags);
244 minor = idr_find(&drm_minors_idr, minor_id);
246 drm_dev_get(minor->dev);
247 spin_unlock_irqrestore(&drm_minor_lock, flags);
250 return ERR_PTR(-ENODEV);
251 } else if (drm_dev_is_unplugged(minor->dev)) {
252 drm_dev_put(minor->dev);
253 return ERR_PTR(-ENODEV);
259 void drm_minor_release(struct drm_minor *minor)
261 drm_dev_put(minor->dev);
265 * DOC: driver instance overview
267 * A device instance for a drm driver is represented by &struct drm_device. This
268 * is allocated and initialized with devm_drm_dev_alloc(), usually from
269 * bus-specific ->probe() callbacks implemented by the driver. The driver then
270 * needs to initialize all the various subsystems for the drm device like memory
271 * management, vblank handling, modesetting support and initial output
272 * configuration plus obviously initialize all the corresponding hardware bits.
273 * Finally when everything is up and running and ready for userspace the device
274 * instance can be published using drm_dev_register().
276 * There is also deprecated support for initializing device instances using
277 * bus-specific helpers and the &drm_driver.load callback. But due to
278 * backwards-compatibility needs the device instance have to be published too
279 * early, which requires unpretty global locking to make safe and is therefore
280 * only support for existing drivers not yet converted to the new scheme.
282 * When cleaning up a device instance everything needs to be done in reverse:
283 * First unpublish the device instance with drm_dev_unregister(). Then clean up
284 * any other resources allocated at device initialization and drop the driver's
285 * reference to &drm_device using drm_dev_put().
287 * Note that any allocation or resource which is visible to userspace must be
288 * released only when the final drm_dev_put() is called, and not when the
289 * driver is unbound from the underlying physical struct &device. Best to use
290 * &drm_device managed resources with drmm_add_action(), drmm_kmalloc() and
293 * devres managed resources like devm_kmalloc() can only be used for resources
294 * directly related to the underlying hardware device, and only used in code
295 * paths fully protected by drm_dev_enter() and drm_dev_exit().
297 * Display driver example
298 * ~~~~~~~~~~~~~~~~~~~~~~
300 * The following example shows a typical structure of a DRM display driver.
301 * The example focus on the probe() function and the other functions that is
302 * almost always present and serves as a demonstration of devm_drm_dev_alloc().
306 * struct driver_device {
307 * struct drm_device drm;
308 * void *userspace_facing;
312 * static const struct drm_driver driver_drm_driver = {
316 * static int driver_probe(struct platform_device *pdev)
318 * struct driver_device *priv;
319 * struct drm_device *drm;
322 * priv = devm_drm_dev_alloc(&pdev->dev, &driver_drm_driver,
323 * struct driver_device, drm);
325 * return PTR_ERR(priv);
328 * ret = drmm_mode_config_init(drm);
332 * priv->userspace_facing = drmm_kzalloc(..., GFP_KERNEL);
333 * if (!priv->userspace_facing)
336 * priv->pclk = devm_clk_get(dev, "PCLK");
337 * if (IS_ERR(priv->pclk))
338 * return PTR_ERR(priv->pclk);
340 * // Further setup, display pipeline etc
342 * platform_set_drvdata(pdev, drm);
344 * drm_mode_config_reset(drm);
346 * ret = drm_dev_register(drm);
350 * drm_fbdev_generic_setup(drm, 32);
355 * // This function is called before the devm_ resources are released
356 * static int driver_remove(struct platform_device *pdev)
358 * struct drm_device *drm = platform_get_drvdata(pdev);
360 * drm_dev_unregister(drm);
361 * drm_atomic_helper_shutdown(drm)
366 * // This function is called on kernel restart and shutdown
367 * static void driver_shutdown(struct platform_device *pdev)
369 * drm_atomic_helper_shutdown(platform_get_drvdata(pdev));
372 * static int __maybe_unused driver_pm_suspend(struct device *dev)
374 * return drm_mode_config_helper_suspend(dev_get_drvdata(dev));
377 * static int __maybe_unused driver_pm_resume(struct device *dev)
379 * drm_mode_config_helper_resume(dev_get_drvdata(dev));
384 * static const struct dev_pm_ops driver_pm_ops = {
385 * SET_SYSTEM_SLEEP_PM_OPS(driver_pm_suspend, driver_pm_resume)
388 * static struct platform_driver driver_driver = {
391 * .pm = &driver_pm_ops,
393 * .probe = driver_probe,
394 * .remove = driver_remove,
395 * .shutdown = driver_shutdown,
397 * module_platform_driver(driver_driver);
399 * Drivers that want to support device unplugging (USB, DT overlay unload) should
400 * use drm_dev_unplug() instead of drm_dev_unregister(). The driver must protect
401 * regions that is accessing device resources to prevent use after they're
402 * released. This is done using drm_dev_enter() and drm_dev_exit(). There is one
403 * shortcoming however, drm_dev_unplug() marks the drm_device as unplugged before
404 * drm_atomic_helper_shutdown() is called. This means that if the disable code
405 * paths are protected, they will not run on regular driver module unload,
406 * possibly leaving the hardware enabled.
410 * drm_put_dev - Unregister and release a DRM device
413 * Called at module unload time or when a PCI device is unplugged.
415 * Cleans up all DRM device, calling drm_lastclose().
417 * Note: Use of this function is deprecated. It will eventually go away
418 * completely. Please use drm_dev_unregister() and drm_dev_put() explicitly
419 * instead to make sure that the device isn't userspace accessible any more
420 * while teardown is in progress, ensuring that userspace can't access an
421 * inconsistent state.
423 void drm_put_dev(struct drm_device *dev)
428 DRM_ERROR("cleanup called no dev\n");
432 drm_dev_unregister(dev);
435 EXPORT_SYMBOL(drm_put_dev);
438 * drm_dev_enter - Enter device critical section
440 * @idx: Pointer to index that will be passed to the matching drm_dev_exit()
442 * This function marks and protects the beginning of a section that should not
443 * be entered after the device has been unplugged. The section end is marked
444 * with drm_dev_exit(). Calls to this function can be nested.
447 * True if it is OK to enter the section, false otherwise.
449 bool drm_dev_enter(struct drm_device *dev, int *idx)
451 *idx = srcu_read_lock(&drm_unplug_srcu);
453 if (dev->unplugged) {
454 srcu_read_unlock(&drm_unplug_srcu, *idx);
460 EXPORT_SYMBOL(drm_dev_enter);
463 * drm_dev_exit - Exit device critical section
464 * @idx: index returned from drm_dev_enter()
466 * This function marks the end of a section that should not be entered after
467 * the device has been unplugged.
469 void drm_dev_exit(int idx)
471 srcu_read_unlock(&drm_unplug_srcu, idx);
473 EXPORT_SYMBOL(drm_dev_exit);
476 * drm_dev_unplug - unplug a DRM device
479 * This unplugs a hotpluggable DRM device, which makes it inaccessible to
480 * userspace operations. Entry-points can use drm_dev_enter() and
481 * drm_dev_exit() to protect device resources in a race free manner. This
482 * essentially unregisters the device like drm_dev_unregister(), but can be
483 * called while there are still open users of @dev.
485 void drm_dev_unplug(struct drm_device *dev)
488 * After synchronizing any critical read section is guaranteed to see
489 * the new value of ->unplugged, and any critical section which might
490 * still have seen the old value of ->unplugged is guaranteed to have
493 dev->unplugged = true;
494 synchronize_srcu(&drm_unplug_srcu);
496 drm_dev_unregister(dev);
498 /* Clear all CPU mappings pointing to this device */
499 unmap_mapping_range(dev->anon_inode->i_mapping, 0, 0, 1);
501 EXPORT_SYMBOL(drm_dev_unplug);
505 * We want to be able to allocate our own "struct address_space" to control
506 * memory-mappings in VRAM (or stolen RAM, ...). However, core MM does not allow
507 * stand-alone address_space objects, so we need an underlying inode. As there
508 * is no way to allocate an independent inode easily, we need a fake internal
511 * The drm_fs_inode_new() function allocates a new inode, drm_fs_inode_free()
512 * frees it again. You are allowed to use iget() and iput() to get references to
513 * the inode. But each drm_fs_inode_new() call must be paired with exactly one
514 * drm_fs_inode_free() call (which does not have to be the last iput()).
515 * We use drm_fs_inode_*() to manage our internal VFS mount-point and share it
516 * between multiple inode-users. You could, technically, call
517 * iget() + drm_fs_inode_free() directly after alloc and sometime later do an
518 * iput(), but this way you'd end up with a new vfsmount for each inode.
521 static int drm_fs_cnt;
522 static struct vfsmount *drm_fs_mnt;
524 static int drm_fs_init_fs_context(struct fs_context *fc)
526 return init_pseudo(fc, 0x010203ff) ? 0 : -ENOMEM;
529 static struct file_system_type drm_fs_type = {
531 .owner = THIS_MODULE,
532 .init_fs_context = drm_fs_init_fs_context,
533 .kill_sb = kill_anon_super,
536 static struct inode *drm_fs_inode_new(void)
541 r = simple_pin_fs(&drm_fs_type, &drm_fs_mnt, &drm_fs_cnt);
543 DRM_ERROR("Cannot mount pseudo fs: %d\n", r);
547 inode = alloc_anon_inode(drm_fs_mnt->mnt_sb);
549 simple_release_fs(&drm_fs_mnt, &drm_fs_cnt);
554 static void drm_fs_inode_free(struct inode *inode)
558 simple_release_fs(&drm_fs_mnt, &drm_fs_cnt);
563 * DOC: component helper usage recommendations
565 * DRM drivers that drive hardware where a logical device consists of a pile of
566 * independent hardware blocks are recommended to use the :ref:`component helper
567 * library<component>`. For consistency and better options for code reuse the
568 * following guidelines apply:
570 * - The entire device initialization procedure should be run from the
571 * &component_master_ops.master_bind callback, starting with
572 * devm_drm_dev_alloc(), then binding all components with
573 * component_bind_all() and finishing with drm_dev_register().
575 * - The opaque pointer passed to all components through component_bind_all()
576 * should point at &struct drm_device of the device instance, not some driver
577 * specific private structure.
579 * - The component helper fills the niche where further standardization of
580 * interfaces is not practical. When there already is, or will be, a
581 * standardized interface like &drm_bridge or &drm_panel, providing its own
582 * functions to find such components at driver load time, like
583 * drm_of_find_panel_or_bridge(), then the component helper should not be
587 static void drm_dev_init_release(struct drm_device *dev, void *res)
589 drm_legacy_ctxbitmap_cleanup(dev);
590 drm_legacy_remove_map_hash(dev);
591 drm_fs_inode_free(dev->anon_inode);
593 put_device(dev->dev);
594 /* Prevent use-after-free in drm_managed_release when debugging is
595 * enabled. Slightly awkward, but can't really be helped. */
597 mutex_destroy(&dev->master_mutex);
598 mutex_destroy(&dev->clientlist_mutex);
599 mutex_destroy(&dev->filelist_mutex);
600 mutex_destroy(&dev->struct_mutex);
601 drm_legacy_destroy_members(dev);
604 static int drm_dev_init(struct drm_device *dev,
605 const struct drm_driver *driver,
606 struct device *parent)
611 if (!drm_core_init_complete) {
612 DRM_ERROR("DRM core is not initialized\n");
616 if (WARN_ON(!parent))
619 kref_init(&dev->ref);
620 dev->dev = get_device(parent);
621 dev->driver = driver;
623 INIT_LIST_HEAD(&dev->managed.resources);
624 spin_lock_init(&dev->managed.lock);
626 /* no per-device feature limits by default */
627 dev->driver_features = ~0u;
629 if (drm_core_check_feature(dev, DRIVER_COMPUTE_ACCEL) &&
630 (drm_core_check_feature(dev, DRIVER_RENDER) ||
631 drm_core_check_feature(dev, DRIVER_MODESET))) {
632 DRM_ERROR("DRM driver can't be both a compute acceleration and graphics driver\n");
636 drm_legacy_init_members(dev);
637 INIT_LIST_HEAD(&dev->filelist);
638 INIT_LIST_HEAD(&dev->filelist_internal);
639 INIT_LIST_HEAD(&dev->clientlist);
640 INIT_LIST_HEAD(&dev->vblank_event_list);
642 spin_lock_init(&dev->event_lock);
643 mutex_init(&dev->struct_mutex);
644 mutex_init(&dev->filelist_mutex);
645 mutex_init(&dev->clientlist_mutex);
646 mutex_init(&dev->master_mutex);
648 ret = drmm_add_action_or_reset(dev, drm_dev_init_release, NULL);
652 inode = drm_fs_inode_new();
654 ret = PTR_ERR(inode);
655 DRM_ERROR("Cannot allocate anonymous inode: %d\n", ret);
659 dev->anon_inode = inode;
661 if (drm_core_check_feature(dev, DRIVER_COMPUTE_ACCEL)) {
662 ret = drm_minor_alloc(dev, DRM_MINOR_ACCEL);
666 if (drm_core_check_feature(dev, DRIVER_RENDER)) {
667 ret = drm_minor_alloc(dev, DRM_MINOR_RENDER);
672 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);
703 static void devm_drm_dev_init_release(void *data)
708 static int devm_drm_dev_init(struct device *parent,
709 struct drm_device *dev,
710 const struct drm_driver *driver)
714 ret = drm_dev_init(dev, driver, parent);
718 return devm_add_action_or_reset(parent,
719 devm_drm_dev_init_release, dev);
722 void *__devm_drm_dev_alloc(struct device *parent,
723 const struct drm_driver *driver,
724 size_t size, size_t offset)
727 struct drm_device *drm;
730 container = kzalloc(size, GFP_KERNEL);
732 return ERR_PTR(-ENOMEM);
734 drm = container + offset;
735 ret = devm_drm_dev_init(parent, drm, driver);
740 drmm_add_final_kfree(drm, container);
744 EXPORT_SYMBOL(__devm_drm_dev_alloc);
747 * drm_dev_alloc - Allocate new DRM device
748 * @driver: DRM driver to allocate device for
749 * @parent: Parent device object
751 * This is the deprecated version of devm_drm_dev_alloc(), which does not support
752 * subclassing through embedding the struct &drm_device in a driver private
753 * structure, and which does not support automatic cleanup through devres.
756 * Pointer to new DRM device, or ERR_PTR on failure.
758 struct drm_device *drm_dev_alloc(const struct drm_driver *driver,
759 struct device *parent)
761 struct drm_device *dev;
764 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
766 return ERR_PTR(-ENOMEM);
768 ret = drm_dev_init(dev, driver, parent);
774 drmm_add_final_kfree(dev, dev);
778 EXPORT_SYMBOL(drm_dev_alloc);
780 static void drm_dev_release(struct kref *ref)
782 struct drm_device *dev = container_of(ref, struct drm_device, ref);
784 if (dev->driver->release)
785 dev->driver->release(dev);
787 drm_managed_release(dev);
789 kfree(dev->managed.final_kfree);
793 * drm_dev_get - Take reference of a DRM device
794 * @dev: device to take reference of or NULL
796 * This increases the ref-count of @dev by one. You *must* already own a
797 * reference when calling this. Use drm_dev_put() to drop this reference
800 * This function never fails. However, this function does not provide *any*
801 * guarantee whether the device is alive or running. It only provides a
802 * reference to the object and the memory associated with it.
804 void drm_dev_get(struct drm_device *dev)
809 EXPORT_SYMBOL(drm_dev_get);
812 * drm_dev_put - Drop reference of a DRM device
813 * @dev: device to drop reference of or NULL
815 * This decreases the ref-count of @dev by one. The device is destroyed if the
816 * ref-count drops to zero.
818 void drm_dev_put(struct drm_device *dev)
821 kref_put(&dev->ref, drm_dev_release);
823 EXPORT_SYMBOL(drm_dev_put);
825 static int create_compat_control_link(struct drm_device *dev)
827 struct drm_minor *minor;
831 if (!drm_core_check_feature(dev, DRIVER_MODESET))
834 minor = *drm_minor_get_slot(dev, DRM_MINOR_PRIMARY);
839 * Some existing userspace out there uses the existing of the controlD*
840 * sysfs files to figure out whether it's a modeset driver. It only does
841 * readdir, hence a symlink is sufficient (and the least confusing
842 * option). Otherwise controlD* is entirely unused.
844 * Old controlD chardev have been allocated in the range
847 name = kasprintf(GFP_KERNEL, "controlD%d", minor->index + 64);
851 ret = sysfs_create_link(minor->kdev->kobj.parent,
860 static void remove_compat_control_link(struct drm_device *dev)
862 struct drm_minor *minor;
865 if (!drm_core_check_feature(dev, DRIVER_MODESET))
868 minor = *drm_minor_get_slot(dev, DRM_MINOR_PRIMARY);
872 name = kasprintf(GFP_KERNEL, "controlD%d", minor->index + 64);
876 sysfs_remove_link(minor->kdev->kobj.parent, name);
882 * drm_dev_register - Register DRM device
883 * @dev: Device to register
884 * @flags: Flags passed to the driver's .load() function
886 * Register the DRM device @dev with the system, advertise device to user-space
887 * and start normal device operation. @dev must be initialized via drm_dev_init()
890 * Never call this twice on any device!
892 * NOTE: To ensure backward compatibility with existing drivers method this
893 * function calls the &drm_driver.load method after registering the device
894 * nodes, creating race conditions. Usage of the &drm_driver.load methods is
895 * therefore deprecated, drivers must perform all initialization before calling
896 * drm_dev_register().
899 * 0 on success, negative error code on failure.
901 int drm_dev_register(struct drm_device *dev, unsigned long flags)
903 const struct drm_driver *driver = dev->driver;
907 drm_mode_config_validate(dev);
909 WARN_ON(!dev->managed.final_kfree);
911 if (drm_dev_needs_global_mutex(dev))
912 mutex_lock(&drm_global_mutex);
914 ret = drm_minor_register(dev, DRM_MINOR_RENDER);
918 ret = drm_minor_register(dev, DRM_MINOR_PRIMARY);
922 ret = drm_minor_register(dev, DRM_MINOR_ACCEL);
926 ret = create_compat_control_link(dev);
930 dev->registered = true;
932 if (dev->driver->load) {
933 ret = dev->driver->load(dev, flags);
938 if (drm_core_check_feature(dev, DRIVER_MODESET))
939 drm_modeset_register_all(dev);
941 DRM_INFO("Initialized %s %d.%d.%d %s for %s on minor %d\n",
942 driver->name, driver->major, driver->minor,
943 driver->patchlevel, driver->date,
944 dev->dev ? dev_name(dev->dev) : "virtual device",
945 dev->primary ? dev->primary->index : dev->accel->index);
950 remove_compat_control_link(dev);
951 drm_minor_unregister(dev, DRM_MINOR_ACCEL);
952 drm_minor_unregister(dev, DRM_MINOR_PRIMARY);
953 drm_minor_unregister(dev, DRM_MINOR_RENDER);
955 if (drm_dev_needs_global_mutex(dev))
956 mutex_unlock(&drm_global_mutex);
959 EXPORT_SYMBOL(drm_dev_register);
962 * drm_dev_unregister - Unregister DRM device
963 * @dev: Device to unregister
965 * Unregister the DRM device from the system. This does the reverse of
966 * drm_dev_register() but does not deallocate the device. The caller must call
967 * drm_dev_put() to drop their final reference.
969 * A special form of unregistering for hotpluggable devices is drm_dev_unplug(),
970 * which can be called while there are still open users of @dev.
972 * This should be called first in the device teardown code to make sure
973 * userspace can't access the device instance any more.
975 void drm_dev_unregister(struct drm_device *dev)
977 if (drm_core_check_feature(dev, DRIVER_LEGACY))
980 dev->registered = false;
982 drm_client_dev_unregister(dev);
984 if (drm_core_check_feature(dev, DRIVER_MODESET))
985 drm_modeset_unregister_all(dev);
987 if (dev->driver->unload)
988 dev->driver->unload(dev);
990 drm_legacy_pci_agp_destroy(dev);
991 drm_legacy_rmmaps(dev);
993 remove_compat_control_link(dev);
994 drm_minor_unregister(dev, DRM_MINOR_ACCEL);
995 drm_minor_unregister(dev, DRM_MINOR_PRIMARY);
996 drm_minor_unregister(dev, DRM_MINOR_RENDER);
998 EXPORT_SYMBOL(drm_dev_unregister);
1001 * drm_dev_set_unique - Set the unique name of a DRM device
1002 * @dev: device of which to set the unique name
1003 * @name: unique name
1005 * Sets the unique name of a DRM device using the specified string. This is
1006 * already done by drm_dev_init(), drivers should only override the default
1007 * unique name for backwards compatibility reasons.
1009 * Return: 0 on success or a negative error code on failure.
1011 int drm_dev_set_unique(struct drm_device *dev, const char *name)
1013 drmm_kfree(dev, dev->unique);
1014 dev->unique = drmm_kstrdup(dev, name, GFP_KERNEL);
1016 return dev->unique ? 0 : -ENOMEM;
1018 EXPORT_SYMBOL(drm_dev_set_unique);
1022 * The DRM core module initializes all global DRM objects and makes them
1023 * available to drivers. Once setup, drivers can probe their respective
1025 * Currently, core management includes:
1026 * - The "DRM-Global" key/value database
1027 * - Global ID management for connectors
1028 * - DRM major number allocation
1029 * - DRM minor management
1031 * - DRM debugfs root
1033 * Furthermore, the DRM core provides dynamic char-dev lookups. For each
1034 * interface registered on a DRM device, you can request minor numbers from DRM
1035 * core. DRM core takes care of major-number management and char-dev
1036 * registration. A stub ->open() callback forwards any open() requests to the
1040 static int drm_stub_open(struct inode *inode, struct file *filp)
1042 const struct file_operations *new_fops;
1043 struct drm_minor *minor;
1048 minor = drm_minor_acquire(iminor(inode));
1050 return PTR_ERR(minor);
1052 new_fops = fops_get(minor->dev->driver->fops);
1058 replace_fops(filp, new_fops);
1059 if (filp->f_op->open)
1060 err = filp->f_op->open(inode, filp);
1065 drm_minor_release(minor);
1070 static const struct file_operations drm_stub_fops = {
1071 .owner = THIS_MODULE,
1072 .open = drm_stub_open,
1073 .llseek = noop_llseek,
1076 static void drm_core_exit(void)
1078 drm_privacy_screen_lookup_exit();
1080 unregister_chrdev(DRM_MAJOR, "drm");
1081 debugfs_remove(drm_debugfs_root);
1082 drm_sysfs_destroy();
1083 idr_destroy(&drm_minors_idr);
1084 drm_connector_ida_destroy();
1087 static int __init drm_core_init(void)
1091 drm_connector_ida_init();
1092 idr_init(&drm_minors_idr);
1093 drm_memcpy_init_early();
1095 ret = drm_sysfs_init();
1097 DRM_ERROR("Cannot create DRM class: %d\n", ret);
1101 drm_debugfs_root = debugfs_create_dir("dri", NULL);
1103 ret = register_chrdev(DRM_MAJOR, "drm", &drm_stub_fops);
1107 ret = accel_core_init();
1111 drm_privacy_screen_lookup_init();
1113 drm_core_init_complete = true;
1115 DRM_DEBUG("Initialized\n");
1123 module_init(drm_core_init);
1124 module_exit(drm_core_exit);