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/slab.h>
36 #include <drm/drm_drv.h>
39 #include "drm_crtc_internal.h"
40 #include "drm_legacy.h"
41 #include "drm_internal.h"
42 #include "drm_crtc_internal.h"
45 * drm_debug: Enable debug output.
46 * Bitmask of DRM_UT_x. See include/drm/drmP.h for details.
48 unsigned int drm_debug
= 0;
49 EXPORT_SYMBOL(drm_debug
);
51 MODULE_AUTHOR("Gareth Hughes, Leif Delgass, José Fonseca, Jon Smirl");
52 MODULE_DESCRIPTION("DRM shared core routines");
53 MODULE_LICENSE("GPL and additional rights");
54 MODULE_PARM_DESC(debug
, "Enable debug output, where each bit enables a debug category.\n"
55 "\t\tBit 0 (0x01) will enable CORE messages (drm core code)\n"
56 "\t\tBit 1 (0x02) will enable DRIVER messages (drm controller code)\n"
57 "\t\tBit 2 (0x04) will enable KMS messages (modesetting code)\n"
58 "\t\tBit 3 (0x08) will enable PRIME messages (prime code)\n"
59 "\t\tBit 4 (0x10) will enable ATOMIC messages (atomic code)\n"
60 "\t\tBit 5 (0x20) will enable VBL messages (vblank code)");
61 module_param_named(debug
, drm_debug
, int, 0600);
63 static DEFINE_SPINLOCK(drm_minor_lock
);
64 static struct idr drm_minors_idr
;
66 static struct dentry
*drm_debugfs_root
;
68 #define DRM_PRINTK_FMT "[" DRM_NAME ":%s]%s %pV"
70 void drm_dev_printk(const struct device
*dev
, const char *level
,
71 unsigned int category
, const char *function_name
,
72 const char *prefix
, const char *format
, ...)
77 if (category
!= DRM_UT_NONE
&& !(drm_debug
& category
))
80 va_start(args
, format
);
85 dev_printk(level
, dev
, DRM_PRINTK_FMT
, function_name
, prefix
,
88 printk("%s" DRM_PRINTK_FMT
, level
, function_name
, prefix
, &vaf
);
92 EXPORT_SYMBOL(drm_dev_printk
);
94 void drm_printk(const char *level
, unsigned int category
,
95 const char *format
, ...)
100 if (category
!= DRM_UT_NONE
&& !(drm_debug
& category
))
103 va_start(args
, format
);
107 printk("%s" "[" DRM_NAME
":%ps]%s %pV",
108 level
, __builtin_return_address(0),
109 strcmp(level
, KERN_ERR
) == 0 ? " *ERROR*" : "", &vaf
);
113 EXPORT_SYMBOL(drm_printk
);
117 * A DRM device can provide several char-dev interfaces on the DRM-Major. Each
118 * of them is represented by a drm_minor object. Depending on the capabilities
119 * of the device-driver, different interfaces are registered.
121 * Minors can be accessed via dev->$minor_name. This pointer is either
122 * NULL or a valid drm_minor pointer and stays valid as long as the device is
123 * valid. This means, DRM minors have the same life-time as the underlying
124 * device. However, this doesn't mean that the minor is active. Minors are
125 * registered and unregistered dynamically according to device-state.
128 static struct drm_minor
**drm_minor_get_slot(struct drm_device
*dev
,
132 case DRM_MINOR_PRIMARY
:
133 return &dev
->primary
;
134 case DRM_MINOR_RENDER
:
136 case DRM_MINOR_CONTROL
:
137 return &dev
->control
;
143 static int drm_minor_alloc(struct drm_device
*dev
, unsigned int type
)
145 struct drm_minor
*minor
;
149 minor
= kzalloc(sizeof(*minor
), GFP_KERNEL
);
156 idr_preload(GFP_KERNEL
);
157 spin_lock_irqsave(&drm_minor_lock
, flags
);
158 r
= idr_alloc(&drm_minors_idr
,
163 spin_unlock_irqrestore(&drm_minor_lock
, flags
);
171 minor
->kdev
= drm_sysfs_minor_alloc(minor
);
172 if (IS_ERR(minor
->kdev
)) {
173 r
= PTR_ERR(minor
->kdev
);
177 *drm_minor_get_slot(dev
, type
) = minor
;
181 spin_lock_irqsave(&drm_minor_lock
, flags
);
182 idr_remove(&drm_minors_idr
, minor
->index
);
183 spin_unlock_irqrestore(&drm_minor_lock
, flags
);
189 static void drm_minor_free(struct drm_device
*dev
, unsigned int type
)
191 struct drm_minor
**slot
, *minor
;
194 slot
= drm_minor_get_slot(dev
, type
);
199 put_device(minor
->kdev
);
201 spin_lock_irqsave(&drm_minor_lock
, flags
);
202 idr_remove(&drm_minors_idr
, minor
->index
);
203 spin_unlock_irqrestore(&drm_minor_lock
, flags
);
209 static int drm_minor_register(struct drm_device
*dev
, unsigned int type
)
211 struct drm_minor
*minor
;
217 minor
= *drm_minor_get_slot(dev
, type
);
221 ret
= drm_debugfs_init(minor
, minor
->index
, drm_debugfs_root
);
223 DRM_ERROR("DRM: Failed to initialize /sys/kernel/debug/dri.\n");
227 ret
= device_add(minor
->kdev
);
231 /* replace NULL with @minor so lookups will succeed from now on */
232 spin_lock_irqsave(&drm_minor_lock
, flags
);
233 idr_replace(&drm_minors_idr
, minor
, minor
->index
);
234 spin_unlock_irqrestore(&drm_minor_lock
, flags
);
236 DRM_DEBUG("new minor registered %d\n", minor
->index
);
240 drm_debugfs_cleanup(minor
);
244 static void drm_minor_unregister(struct drm_device
*dev
, unsigned int type
)
246 struct drm_minor
*minor
;
249 minor
= *drm_minor_get_slot(dev
, type
);
250 if (!minor
|| !device_is_registered(minor
->kdev
))
253 /* replace @minor with NULL so lookups will fail from now on */
254 spin_lock_irqsave(&drm_minor_lock
, flags
);
255 idr_replace(&drm_minors_idr
, NULL
, minor
->index
);
256 spin_unlock_irqrestore(&drm_minor_lock
, flags
);
258 device_del(minor
->kdev
);
259 dev_set_drvdata(minor
->kdev
, NULL
); /* safety belt */
260 drm_debugfs_cleanup(minor
);
264 * Looks up the given minor-ID and returns the respective DRM-minor object. The
265 * refence-count of the underlying device is increased so you must release this
266 * object with drm_minor_release().
268 * As long as you hold this minor, it is guaranteed that the object and the
269 * minor->dev pointer will stay valid! However, the device may get unplugged and
270 * unregistered while you hold the minor.
272 struct drm_minor
*drm_minor_acquire(unsigned int minor_id
)
274 struct drm_minor
*minor
;
277 spin_lock_irqsave(&drm_minor_lock
, flags
);
278 minor
= idr_find(&drm_minors_idr
, minor_id
);
280 drm_dev_ref(minor
->dev
);
281 spin_unlock_irqrestore(&drm_minor_lock
, flags
);
284 return ERR_PTR(-ENODEV
);
285 } else if (drm_device_is_unplugged(minor
->dev
)) {
286 drm_dev_unref(minor
->dev
);
287 return ERR_PTR(-ENODEV
);
293 void drm_minor_release(struct drm_minor
*minor
)
295 drm_dev_unref(minor
->dev
);
299 * DOC: driver instance overview
301 * A device instance for a drm driver is represented by struct &drm_device. This
302 * is allocated with drm_dev_alloc(), usually from bus-specific ->probe()
303 * callbacks implemented by the driver. The driver then needs to initialize all
304 * the various subsystems for the drm device like memory management, vblank
305 * handling, modesetting support and intial output configuration plus obviously
306 * initialize all the corresponding hardware bits. An important part of this is
307 * also calling drm_dev_set_unique() to set the userspace-visible unique name of
308 * this device instance. Finally when everything is up and running and ready for
309 * userspace the device instance can be published using drm_dev_register().
311 * There is also deprecated support for initalizing device instances using
312 * bus-specific helpers and the ->load() callback. But due to
313 * backwards-compatibility needs the device instance have to be published too
314 * early, which requires unpretty global locking to make safe and is therefore
315 * only support for existing drivers not yet converted to the new scheme.
317 * When cleaning up a device instance everything needs to be done in reverse:
318 * First unpublish the device instance with drm_dev_unregister(). Then clean up
319 * any other resources allocated at device initialization and drop the driver's
320 * reference to &drm_device using drm_dev_unref().
322 * Note that the lifetime rules for &drm_device instance has still a lot of
323 * historical baggage. Hence use the reference counting provided by
324 * drm_dev_ref() and drm_dev_unref() only carefully.
326 * Also note that embedding of &drm_device is currently not (yet) supported (but
327 * it would be easy to add). Drivers can store driver-private data in the
328 * dev_priv field of &drm_device.
332 * drm_put_dev - Unregister and release a DRM device
335 * Called at module unload time or when a PCI device is unplugged.
337 * Cleans up all DRM device, calling drm_lastclose().
339 * Note: Use of this function is deprecated. It will eventually go away
340 * completely. Please use drm_dev_unregister() and drm_dev_unref() explicitly
341 * instead to make sure that the device isn't userspace accessible any more
342 * while teardown is in progress, ensuring that userspace can't access an
343 * inconsistent state.
345 void drm_put_dev(struct drm_device
*dev
)
350 DRM_ERROR("cleanup called no dev\n");
354 drm_dev_unregister(dev
);
357 EXPORT_SYMBOL(drm_put_dev
);
359 void drm_unplug_dev(struct drm_device
*dev
)
361 /* for a USB device */
362 drm_dev_unregister(dev
);
364 mutex_lock(&drm_global_mutex
);
366 drm_device_set_unplugged(dev
);
368 if (dev
->open_count
== 0) {
371 mutex_unlock(&drm_global_mutex
);
373 EXPORT_SYMBOL(drm_unplug_dev
);
377 * We want to be able to allocate our own "struct address_space" to control
378 * memory-mappings in VRAM (or stolen RAM, ...). However, core MM does not allow
379 * stand-alone address_space objects, so we need an underlying inode. As there
380 * is no way to allocate an independent inode easily, we need a fake internal
383 * The drm_fs_inode_new() function allocates a new inode, drm_fs_inode_free()
384 * frees it again. You are allowed to use iget() and iput() to get references to
385 * the inode. But each drm_fs_inode_new() call must be paired with exactly one
386 * drm_fs_inode_free() call (which does not have to be the last iput()).
387 * We use drm_fs_inode_*() to manage our internal VFS mount-point and share it
388 * between multiple inode-users. You could, technically, call
389 * iget() + drm_fs_inode_free() directly after alloc and sometime later do an
390 * iput(), but this way you'd end up with a new vfsmount for each inode.
393 static int drm_fs_cnt
;
394 static struct vfsmount
*drm_fs_mnt
;
396 static const struct dentry_operations drm_fs_dops
= {
397 .d_dname
= simple_dname
,
400 static const struct super_operations drm_fs_sops
= {
401 .statfs
= simple_statfs
,
404 static struct dentry
*drm_fs_mount(struct file_system_type
*fs_type
, int flags
,
405 const char *dev_name
, void *data
)
407 return mount_pseudo(fs_type
,
414 static struct file_system_type drm_fs_type
= {
416 .owner
= THIS_MODULE
,
417 .mount
= drm_fs_mount
,
418 .kill_sb
= kill_anon_super
,
421 static struct inode
*drm_fs_inode_new(void)
426 r
= simple_pin_fs(&drm_fs_type
, &drm_fs_mnt
, &drm_fs_cnt
);
428 DRM_ERROR("Cannot mount pseudo fs: %d\n", r
);
432 inode
= alloc_anon_inode(drm_fs_mnt
->mnt_sb
);
434 simple_release_fs(&drm_fs_mnt
, &drm_fs_cnt
);
439 static void drm_fs_inode_free(struct inode
*inode
)
443 simple_release_fs(&drm_fs_mnt
, &drm_fs_cnt
);
448 * drm_dev_init - Initialise new DRM device
450 * @driver: DRM driver
451 * @parent: Parent device object
453 * Initialize a new DRM device. No device registration is done.
454 * Call drm_dev_register() to advertice the device to user space and register it
455 * with other core subsystems. This should be done last in the device
456 * initialization sequence to make sure userspace can't access an inconsistent
459 * The initial ref-count of the object is 1. Use drm_dev_ref() and
460 * drm_dev_unref() to take and drop further ref-counts.
462 * Note that for purely virtual devices @parent can be NULL.
464 * Drivers that do not want to allocate their own device struct
465 * embedding struct &drm_device can call drm_dev_alloc() instead.
468 * 0 on success, or error code on failure.
470 int drm_dev_init(struct drm_device
*dev
,
471 struct drm_driver
*driver
,
472 struct device
*parent
)
476 kref_init(&dev
->ref
);
478 dev
->driver
= driver
;
480 INIT_LIST_HEAD(&dev
->filelist
);
481 INIT_LIST_HEAD(&dev
->ctxlist
);
482 INIT_LIST_HEAD(&dev
->vmalist
);
483 INIT_LIST_HEAD(&dev
->maplist
);
484 INIT_LIST_HEAD(&dev
->vblank_event_list
);
486 spin_lock_init(&dev
->buf_lock
);
487 spin_lock_init(&dev
->event_lock
);
488 mutex_init(&dev
->struct_mutex
);
489 mutex_init(&dev
->filelist_mutex
);
490 mutex_init(&dev
->ctxlist_mutex
);
491 mutex_init(&dev
->master_mutex
);
493 dev
->anon_inode
= drm_fs_inode_new();
494 if (IS_ERR(dev
->anon_inode
)) {
495 ret
= PTR_ERR(dev
->anon_inode
);
496 DRM_ERROR("Cannot allocate anonymous inode: %d\n", ret
);
500 if (drm_core_check_feature(dev
, DRIVER_RENDER
)) {
501 ret
= drm_minor_alloc(dev
, DRM_MINOR_RENDER
);
506 ret
= drm_minor_alloc(dev
, DRM_MINOR_PRIMARY
);
510 ret
= drm_ht_create(&dev
->map_hash
, 12);
514 drm_legacy_ctxbitmap_init(dev
);
516 if (drm_core_check_feature(dev
, DRIVER_GEM
)) {
517 ret
= drm_gem_init(dev
);
519 DRM_ERROR("Cannot initialize graphics execution manager (GEM)\n");
524 /* Use the parent device name as DRM device unique identifier, but fall
525 * back to the driver name for virtual devices like vgem. */
526 ret
= drm_dev_set_unique(dev
, parent
? dev_name(parent
) : driver
->name
);
533 if (drm_core_check_feature(dev
, DRIVER_GEM
))
534 drm_gem_destroy(dev
);
536 drm_legacy_ctxbitmap_cleanup(dev
);
537 drm_ht_remove(&dev
->map_hash
);
539 drm_minor_free(dev
, DRM_MINOR_PRIMARY
);
540 drm_minor_free(dev
, DRM_MINOR_RENDER
);
541 drm_minor_free(dev
, DRM_MINOR_CONTROL
);
542 drm_fs_inode_free(dev
->anon_inode
);
544 mutex_destroy(&dev
->master_mutex
);
545 mutex_destroy(&dev
->ctxlist_mutex
);
546 mutex_destroy(&dev
->filelist_mutex
);
547 mutex_destroy(&dev
->struct_mutex
);
550 EXPORT_SYMBOL(drm_dev_init
);
553 * drm_dev_alloc - Allocate new DRM device
554 * @driver: DRM driver to allocate device for
555 * @parent: Parent device object
557 * Allocate and initialize a new DRM device. No device registration is done.
558 * Call drm_dev_register() to advertice the device to user space and register it
559 * with other core subsystems. This should be done last in the device
560 * initialization sequence to make sure userspace can't access an inconsistent
563 * The initial ref-count of the object is 1. Use drm_dev_ref() and
564 * drm_dev_unref() to take and drop further ref-counts.
566 * Note that for purely virtual devices @parent can be NULL.
568 * Drivers that wish to subclass or embed struct &drm_device into their
569 * own struct should look at using drm_dev_init() instead.
572 * Pointer to new DRM device, or ERR_PTR on failure.
574 struct drm_device
*drm_dev_alloc(struct drm_driver
*driver
,
575 struct device
*parent
)
577 struct drm_device
*dev
;
580 dev
= kzalloc(sizeof(*dev
), GFP_KERNEL
);
582 return ERR_PTR(-ENOMEM
);
584 ret
= drm_dev_init(dev
, driver
, parent
);
592 EXPORT_SYMBOL(drm_dev_alloc
);
594 static void drm_dev_release(struct kref
*ref
)
596 struct drm_device
*dev
= container_of(ref
, struct drm_device
, ref
);
598 if (drm_core_check_feature(dev
, DRIVER_GEM
))
599 drm_gem_destroy(dev
);
601 drm_legacy_ctxbitmap_cleanup(dev
);
602 drm_ht_remove(&dev
->map_hash
);
603 drm_fs_inode_free(dev
->anon_inode
);
605 drm_minor_free(dev
, DRM_MINOR_PRIMARY
);
606 drm_minor_free(dev
, DRM_MINOR_RENDER
);
607 drm_minor_free(dev
, DRM_MINOR_CONTROL
);
609 mutex_destroy(&dev
->master_mutex
);
610 mutex_destroy(&dev
->ctxlist_mutex
);
611 mutex_destroy(&dev
->filelist_mutex
);
612 mutex_destroy(&dev
->struct_mutex
);
618 * drm_dev_ref - Take reference of a DRM device
619 * @dev: device to take reference of or NULL
621 * This increases the ref-count of @dev by one. You *must* already own a
622 * reference when calling this. Use drm_dev_unref() to drop this reference
625 * This function never fails. However, this function does not provide *any*
626 * guarantee whether the device is alive or running. It only provides a
627 * reference to the object and the memory associated with it.
629 void drm_dev_ref(struct drm_device
*dev
)
634 EXPORT_SYMBOL(drm_dev_ref
);
637 * drm_dev_unref - Drop reference of a DRM device
638 * @dev: device to drop reference of or NULL
640 * This decreases the ref-count of @dev by one. The device is destroyed if the
641 * ref-count drops to zero.
643 void drm_dev_unref(struct drm_device
*dev
)
646 kref_put(&dev
->ref
, drm_dev_release
);
648 EXPORT_SYMBOL(drm_dev_unref
);
650 static int create_compat_control_link(struct drm_device
*dev
)
652 struct drm_minor
*minor
;
656 if (!drm_core_check_feature(dev
, DRIVER_MODESET
))
659 minor
= *drm_minor_get_slot(dev
, DRM_MINOR_PRIMARY
);
664 * Some existing userspace out there uses the existing of the controlD*
665 * sysfs files to figure out whether it's a modeset driver. It only does
666 * readdir, hence a symlink is sufficient (and the least confusing
667 * option). Otherwise controlD* is entirely unused.
669 * Old controlD chardev have been allocated in the range
672 name
= kasprintf(GFP_KERNEL
, "controlD%d", minor
->index
+ 64);
676 ret
= sysfs_create_link(minor
->kdev
->kobj
.parent
,
685 static void remove_compat_control_link(struct drm_device
*dev
)
687 struct drm_minor
*minor
;
690 if (!drm_core_check_feature(dev
, DRIVER_MODESET
))
693 minor
= *drm_minor_get_slot(dev
, DRM_MINOR_PRIMARY
);
697 name
= kasprintf(GFP_KERNEL
, "controlD%d", minor
->index
);
701 sysfs_remove_link(minor
->kdev
->kobj
.parent
, name
);
707 * drm_dev_register - Register DRM device
708 * @dev: Device to register
709 * @flags: Flags passed to the driver's .load() function
711 * Register the DRM device @dev with the system, advertise device to user-space
712 * and start normal device operation. @dev must be allocated via drm_dev_alloc()
715 * Never call this twice on any device!
717 * NOTE: To ensure backward compatibility with existing drivers method this
718 * function calls the ->load() method after registering the device nodes,
719 * creating race conditions. Usage of the ->load() methods is therefore
720 * deprecated, drivers must perform all initialization before calling
721 * drm_dev_register().
724 * 0 on success, negative error code on failure.
726 int drm_dev_register(struct drm_device
*dev
, unsigned long flags
)
730 mutex_lock(&drm_global_mutex
);
732 ret
= drm_minor_register(dev
, DRM_MINOR_CONTROL
);
736 ret
= drm_minor_register(dev
, DRM_MINOR_RENDER
);
740 ret
= drm_minor_register(dev
, DRM_MINOR_PRIMARY
);
744 ret
= create_compat_control_link(dev
);
748 dev
->registered
= true;
750 if (dev
->driver
->load
) {
751 ret
= dev
->driver
->load(dev
, flags
);
756 if (drm_core_check_feature(dev
, DRIVER_MODESET
))
757 drm_modeset_register_all(dev
);
763 remove_compat_control_link(dev
);
764 drm_minor_unregister(dev
, DRM_MINOR_PRIMARY
);
765 drm_minor_unregister(dev
, DRM_MINOR_RENDER
);
766 drm_minor_unregister(dev
, DRM_MINOR_CONTROL
);
768 mutex_unlock(&drm_global_mutex
);
771 EXPORT_SYMBOL(drm_dev_register
);
774 * drm_dev_unregister - Unregister DRM device
775 * @dev: Device to unregister
777 * Unregister the DRM device from the system. This does the reverse of
778 * drm_dev_register() but does not deallocate the device. The caller must call
779 * drm_dev_unref() to drop their final reference.
781 * This should be called first in the device teardown code to make sure
782 * userspace can't access the device instance any more.
784 void drm_dev_unregister(struct drm_device
*dev
)
786 struct drm_map_list
*r_list
, *list_temp
;
790 dev
->registered
= false;
792 if (drm_core_check_feature(dev
, DRIVER_MODESET
))
793 drm_modeset_unregister_all(dev
);
795 if (dev
->driver
->unload
)
796 dev
->driver
->unload(dev
);
799 drm_pci_agp_destroy(dev
);
801 drm_vblank_cleanup(dev
);
803 list_for_each_entry_safe(r_list
, list_temp
, &dev
->maplist
, head
)
804 drm_legacy_rmmap(dev
, r_list
->map
);
806 remove_compat_control_link(dev
);
807 drm_minor_unregister(dev
, DRM_MINOR_PRIMARY
);
808 drm_minor_unregister(dev
, DRM_MINOR_RENDER
);
809 drm_minor_unregister(dev
, DRM_MINOR_CONTROL
);
811 EXPORT_SYMBOL(drm_dev_unregister
);
814 * drm_dev_set_unique - Set the unique name of a DRM device
815 * @dev: device of which to set the unique name
818 * Sets the unique name of a DRM device using the specified string. Drivers
819 * can use this at driver probe time if the unique name of the devices they
822 * Return: 0 on success or a negative error code on failure.
824 int drm_dev_set_unique(struct drm_device
*dev
, const char *name
)
827 dev
->unique
= kstrdup(name
, GFP_KERNEL
);
829 return dev
->unique
? 0 : -ENOMEM
;
831 EXPORT_SYMBOL(drm_dev_set_unique
);
835 * The DRM core module initializes all global DRM objects and makes them
836 * available to drivers. Once setup, drivers can probe their respective
838 * Currently, core management includes:
839 * - The "DRM-Global" key/value database
840 * - Global ID management for connectors
841 * - DRM major number allocation
842 * - DRM minor management
846 * Furthermore, the DRM core provides dynamic char-dev lookups. For each
847 * interface registered on a DRM device, you can request minor numbers from DRM
848 * core. DRM core takes care of major-number management and char-dev
849 * registration. A stub ->open() callback forwards any open() requests to the
853 static int drm_stub_open(struct inode
*inode
, struct file
*filp
)
855 const struct file_operations
*new_fops
;
856 struct drm_minor
*minor
;
861 mutex_lock(&drm_global_mutex
);
862 minor
= drm_minor_acquire(iminor(inode
));
864 err
= PTR_ERR(minor
);
868 new_fops
= fops_get(minor
->dev
->driver
->fops
);
874 replace_fops(filp
, new_fops
);
875 if (filp
->f_op
->open
)
876 err
= filp
->f_op
->open(inode
, filp
);
881 drm_minor_release(minor
);
883 mutex_unlock(&drm_global_mutex
);
887 static const struct file_operations drm_stub_fops
= {
888 .owner
= THIS_MODULE
,
889 .open
= drm_stub_open
,
890 .llseek
= noop_llseek
,
893 static void drm_core_exit(void)
895 unregister_chrdev(DRM_MAJOR
, "drm");
896 debugfs_remove(drm_debugfs_root
);
898 idr_destroy(&drm_minors_idr
);
899 drm_connector_ida_destroy();
900 drm_global_release();
903 static int __init
drm_core_init(void)
908 drm_connector_ida_init();
909 idr_init(&drm_minors_idr
);
911 ret
= drm_sysfs_init();
913 DRM_ERROR("Cannot create DRM class: %d\n", ret
);
917 drm_debugfs_root
= debugfs_create_dir("dri", NULL
);
918 if (!drm_debugfs_root
) {
920 DRM_ERROR("Cannot create debugfs-root: %d\n", ret
);
924 ret
= register_chrdev(DRM_MAJOR
, "drm", &drm_stub_fops
);
928 DRM_INFO("Initialized\n");
936 module_init(drm_core_init
);
937 module_exit(drm_core_exit
);