drm: move drm_stub.c to drm_drv.c

Everyone agrees we should do this,

Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 921 insertions, 0 deletions

diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
new file mode 100644
index 000000000000..92bc6b1d9646
--- /dev/null
+++ b/drivers/gpu/drm/drm_drv.c
@@ -0,0 +1,921 @@
+/*
+ * Created: Fri Jan 19 10:48:35 2001 by faith@acm.org
+ *
+ * Copyright 2001 VA Linux Systems, Inc., Sunnyvale, California.
+ * All Rights Reserved.
+ *
+ * Author Rickard E. (Rik) Faith <faith@valinux.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * PRECISION INSIGHT AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+#include <linux/debugfs.h>
+#include <linux/fs.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/mount.h>
+#include <linux/slab.h>
+#include <drm/drmP.h>
+#include <drm/drm_core.h>
+#include "drm_legacy.h"
+
+unsigned int drm_debug = 0;	/* 1 to enable debug output */
+EXPORT_SYMBOL(drm_debug);
+
+unsigned int drm_vblank_offdelay = 5000;    /* Default to 5000 msecs. */
+
+unsigned int drm_timestamp_precision = 20;  /* Default to 20 usecs. */
+
+/*
+ * Default to use monotonic timestamps for wait-for-vblank and page-flip
+ * complete events.
+ */
+unsigned int drm_timestamp_monotonic = 1;
+
+MODULE_AUTHOR(CORE_AUTHOR);
+MODULE_DESCRIPTION(CORE_DESC);
+MODULE_LICENSE("GPL and additional rights");
+MODULE_PARM_DESC(debug, "Enable debug output");
+MODULE_PARM_DESC(vblankoffdelay, "Delay until vblank irq auto-disable [msecs]");
+MODULE_PARM_DESC(timestamp_precision_usec, "Max. error on timestamps [usecs]");
+MODULE_PARM_DESC(timestamp_monotonic, "Use monotonic timestamps");
+
+module_param_named(debug, drm_debug, int, 0600);
+module_param_named(vblankoffdelay, drm_vblank_offdelay, int, 0600);
+module_param_named(timestamp_precision_usec, drm_timestamp_precision, int, 0600);
+module_param_named(timestamp_monotonic, drm_timestamp_monotonic, int, 0600);
+
+static DEFINE_SPINLOCK(drm_minor_lock);
+static struct idr drm_minors_idr;
+
+struct class *drm_class;
+static struct dentry *drm_debugfs_root;
+
+int drm_err(const char *func, const char *format, ...)
+{
+	struct va_format vaf;
+	va_list args;
+	int r;
+
+	va_start(args, format);
+
+	vaf.fmt = format;
+	vaf.va = &args;
+
+	r = printk(KERN_ERR "[" DRM_NAME ":%s] *ERROR* %pV", func, &vaf);
+
+	va_end(args);
+
+	return r;
+}
+EXPORT_SYMBOL(drm_err);
+
+void drm_ut_debug_printk(const char *function_name, const char *format, ...)
+{
+	struct va_format vaf;
+	va_list args;
+
+	va_start(args, format);
+	vaf.fmt = format;
+	vaf.va = &args;
+
+	printk(KERN_DEBUG "[" DRM_NAME ":%s] %pV", function_name, &vaf);
+
+	va_end(args);
+}
+EXPORT_SYMBOL(drm_ut_debug_printk);
+
+struct drm_master *drm_master_create(struct drm_minor *minor)
+{
+	struct drm_master *master;
+
+	master = kzalloc(sizeof(*master), GFP_KERNEL);
+	if (!master)
+		return NULL;
+
+	kref_init(&master->refcount);
+	spin_lock_init(&master->lock.spinlock);
+	init_waitqueue_head(&master->lock.lock_queue);
+	if (drm_ht_create(&master->magiclist, DRM_MAGIC_HASH_ORDER)) {
+		kfree(master);
+		return NULL;
+	}
+	INIT_LIST_HEAD(&master->magicfree);
+	master->minor = minor;
+
+	return master;
+}
+
+struct drm_master *drm_master_get(struct drm_master *master)
+{
+	kref_get(&master->refcount);
+	return master;
+}
+EXPORT_SYMBOL(drm_master_get);
+
+static void drm_master_destroy(struct kref *kref)
+{
+	struct drm_master *master = container_of(kref, struct drm_master, refcount);
+	struct drm_magic_entry *pt, *next;
+	struct drm_device *dev = master->minor->dev;
+	struct drm_map_list *r_list, *list_temp;
+
+	mutex_lock(&dev->struct_mutex);
+	if (dev->driver->master_destroy)
+		dev->driver->master_destroy(dev, master);
+
+	list_for_each_entry_safe(r_list, list_temp, &dev->maplist, head) {
+		if (r_list->master == master) {
+			drm_rmmap_locked(dev, r_list->map);
+			r_list = NULL;
+		}
+	}
+
+	if (master->unique) {
+		kfree(master->unique);
+		master->unique = NULL;
+		master->unique_len = 0;
+	}
+
+	list_for_each_entry_safe(pt, next, &master->magicfree, head) {
+		list_del(&pt->head);
+		drm_ht_remove_item(&master->magiclist, &pt->hash_item);
+		kfree(pt);
+	}
+
+	drm_ht_remove(&master->magiclist);
+
+	mutex_unlock(&dev->struct_mutex);
+	kfree(master);
+}
+
+void drm_master_put(struct drm_master **master)
+{
+	kref_put(&(*master)->refcount, drm_master_destroy);
+	*master = NULL;
+}
+EXPORT_SYMBOL(drm_master_put);
+
+int drm_setmaster_ioctl(struct drm_device *dev, void *data,
+			struct drm_file *file_priv)
+{
+	int ret = 0;
+
+	mutex_lock(&dev->master_mutex);
+	if (drm_is_master(file_priv))
+		goto out_unlock;
+
+	if (file_priv->minor->master) {
+		ret = -EINVAL;
+		goto out_unlock;
+	}
+
+	if (!file_priv->master) {
+		ret = -EINVAL;
+		goto out_unlock;
+	}
+
+	file_priv->minor->master = drm_master_get(file_priv->master);
+	if (dev->driver->master_set) {
+		ret = dev->driver->master_set(dev, file_priv, false);
+		if (unlikely(ret != 0))
+			drm_master_put(&file_priv->minor->master);
+	}
+
+out_unlock:
+	mutex_unlock(&dev->master_mutex);
+	return ret;
+}
+
+int drm_dropmaster_ioctl(struct drm_device *dev, void *data,
+			 struct drm_file *file_priv)
+{
+	int ret = -EINVAL;
+
+	mutex_lock(&dev->master_mutex);
+	if (!drm_is_master(file_priv))
+		goto out_unlock;
+
+	if (!file_priv->minor->master)
+		goto out_unlock;
+
+	ret = 0;
+	if (dev->driver->master_drop)
+		dev->driver->master_drop(dev, file_priv, false);
+	drm_master_put(&file_priv->minor->master);
+
+out_unlock:
+	mutex_unlock(&dev->master_mutex);
+	return ret;
+}
+
+/*
+ * DRM Minors
+ * A DRM device can provide several char-dev interfaces on the DRM-Major. Each
+ * of them is represented by a drm_minor object. Depending on the capabilities
+ * of the device-driver, different interfaces are registered.
+ *
+ * Minors can be accessed via dev->$minor_name. This pointer is either
+ * NULL or a valid drm_minor pointer and stays valid as long as the device is
+ * valid. This means, DRM minors have the same life-time as the underlying
+ * device. However, this doesn't mean that the minor is active. Minors are
+ * registered and unregistered dynamically according to device-state.
+ */
+
+static struct drm_minor **drm_minor_get_slot(struct drm_device *dev,
+					     unsigned int type)
+{
+	switch (type) {
+	case DRM_MINOR_LEGACY:
+		return &dev->primary;
+	case DRM_MINOR_RENDER:
+		return &dev->render;
+	case DRM_MINOR_CONTROL:
+		return &dev->control;
+	default:
+		return NULL;
+	}
+}
+
+static int drm_minor_alloc(struct drm_device *dev, unsigned int type)
+{
+	struct drm_minor *minor;
+	unsigned long flags;
+	int r;
+
+	minor = kzalloc(sizeof(*minor), GFP_KERNEL);
+	if (!minor)
+		return -ENOMEM;
+
+	minor->type = type;
+	minor->dev = dev;
+
+	idr_preload(GFP_KERNEL);
+	spin_lock_irqsave(&drm_minor_lock, flags);
+	r = idr_alloc(&drm_minors_idr,
+		      NULL,
+		      64 * type,
+		      64 * (type + 1),
+		      GFP_NOWAIT);
+	spin_unlock_irqrestore(&drm_minor_lock, flags);
+	idr_preload_end();
+
+	if (r < 0)
+		goto err_free;
+
+	minor->index = r;
+
+	minor->kdev = drm_sysfs_minor_alloc(minor);
+	if (IS_ERR(minor->kdev)) {
+		r = PTR_ERR(minor->kdev);
+		goto err_index;
+	}
+
+	*drm_minor_get_slot(dev, type) = minor;
+	return 0;
+
+err_index:
+	spin_lock_irqsave(&drm_minor_lock, flags);
+	idr_remove(&drm_minors_idr, minor->index);
+	spin_unlock_irqrestore(&drm_minor_lock, flags);
+err_free:
+	kfree(minor);
+	return r;
+}
+
+static void drm_minor_free(struct drm_device *dev, unsigned int type)
+{
+	struct drm_minor **slot, *minor;
+	unsigned long flags;
+
+	slot = drm_minor_get_slot(dev, type);
+	minor = *slot;
+	if (!minor)
+		return;
+
+	drm_mode_group_destroy(&minor->mode_group);
+	put_device(minor->kdev);
+
+	spin_lock_irqsave(&drm_minor_lock, flags);
+	idr_remove(&drm_minors_idr, minor->index);
+	spin_unlock_irqrestore(&drm_minor_lock, flags);
+
+	kfree(minor);
+	*slot = NULL;
+}
+
+static int drm_minor_register(struct drm_device *dev, unsigned int type)
+{
+	struct drm_minor *minor;
+	unsigned long flags;
+	int ret;
+
+	DRM_DEBUG("\n");
+
+	minor = *drm_minor_get_slot(dev, type);
+	if (!minor)
+		return 0;
+
+	ret = drm_debugfs_init(minor, minor->index, drm_debugfs_root);
+	if (ret) {
+		DRM_ERROR("DRM: Failed to initialize /sys/kernel/debug/dri.\n");
+		return ret;
+	}
+
+	ret = device_add(minor->kdev);
+	if (ret)
+		goto err_debugfs;
+
+	/* replace NULL with @minor so lookups will succeed from now on */
+	spin_lock_irqsave(&drm_minor_lock, flags);
+	idr_replace(&drm_minors_idr, minor, minor->index);
+	spin_unlock_irqrestore(&drm_minor_lock, flags);
+
+	DRM_DEBUG("new minor registered %d\n", minor->index);
+	return 0;
+
+err_debugfs:
+	drm_debugfs_cleanup(minor);
+	return ret;
+}
+
+static void drm_minor_unregister(struct drm_device *dev, unsigned int type)
+{
+	struct drm_minor *minor;
+	unsigned long flags;
+
+	minor = *drm_minor_get_slot(dev, type);
+	if (!minor || !device_is_registered(minor->kdev))
+		return;
+
+	/* replace @minor with NULL so lookups will fail from now on */
+	spin_lock_irqsave(&drm_minor_lock, flags);
+	idr_replace(&drm_minors_idr, NULL, minor->index);
+	spin_unlock_irqrestore(&drm_minor_lock, flags);
+
+	device_del(minor->kdev);
+	dev_set_drvdata(minor->kdev, NULL); /* safety belt */
+	drm_debugfs_cleanup(minor);
+}
+
+/**
+ * drm_minor_acquire - Acquire a DRM minor
+ * @minor_id: Minor ID of the DRM-minor
+ *
+ * Looks up the given minor-ID and returns the respective DRM-minor object. The
+ * refence-count of the underlying device is increased so you must release this
+ * object with drm_minor_release().
+ *
+ * As long as you hold this minor, it is guaranteed that the object and the
+ * minor->dev pointer will stay valid! However, the device may get unplugged and
+ * unregistered while you hold the minor.
+ *
+ * Returns:
+ * Pointer to minor-object with increased device-refcount, or PTR_ERR on
+ * failure.
+ */
+struct drm_minor *drm_minor_acquire(unsigned int minor_id)
+{
+	struct drm_minor *minor;
+	unsigned long flags;
+
+	spin_lock_irqsave(&drm_minor_lock, flags);
+	minor = idr_find(&drm_minors_idr, minor_id);
+	if (minor)
+		drm_dev_ref(minor->dev);
+	spin_unlock_irqrestore(&drm_minor_lock, flags);
+
+	if (!minor) {
+		return ERR_PTR(-ENODEV);
+	} else if (drm_device_is_unplugged(minor->dev)) {
+		drm_dev_unref(minor->dev);
+		return ERR_PTR(-ENODEV);
+	}
+
+	return minor;
+}
+
+/**
+ * drm_minor_release - Release DRM minor
+ * @minor: Pointer to DRM minor object
+ *
+ * Release a minor that was previously acquired via drm_minor_acquire().
+ */
+void drm_minor_release(struct drm_minor *minor)
+{
+	drm_dev_unref(minor->dev);
+}
+
+/**
+ * drm_put_dev - Unregister and release a DRM device
+ * @dev: DRM device
+ *
+ * Called at module unload time or when a PCI device is unplugged.
+ *
+ * Use of this function is discouraged. It will eventually go away completely.
+ * Please use drm_dev_unregister() and drm_dev_unref() explicitly instead.
+ *
+ * Cleans up all DRM device, calling drm_lastclose().
+ */
+void drm_put_dev(struct drm_device *dev)
+{
+	DRM_DEBUG("\n");
+
+	if (!dev) {
+		DRM_ERROR("cleanup called no dev\n");
+		return;
+	}
+
+	drm_dev_unregister(dev);
+	drm_dev_unref(dev);
+}
+EXPORT_SYMBOL(drm_put_dev);
+
+void drm_unplug_dev(struct drm_device *dev)
+{
+	/* for a USB device */
+	drm_minor_unregister(dev, DRM_MINOR_LEGACY);
+	drm_minor_unregister(dev, DRM_MINOR_RENDER);
+	drm_minor_unregister(dev, DRM_MINOR_CONTROL);
+
+	mutex_lock(&drm_global_mutex);
+
+	drm_device_set_unplugged(dev);
+
+	if (dev->open_count == 0) {
+		drm_put_dev(dev);
+	}
+	mutex_unlock(&drm_global_mutex);
+}
+EXPORT_SYMBOL(drm_unplug_dev);
+
+/*
+ * DRM internal mount
+ * We want to be able to allocate our own "struct address_space" to control
+ * memory-mappings in VRAM (or stolen RAM, ...). However, core MM does not allow
+ * stand-alone address_space objects, so we need an underlying inode. As there
+ * is no way to allocate an independent inode easily, we need a fake internal
+ * VFS mount-point.
+ *
+ * The drm_fs_inode_new() function allocates a new inode, drm_fs_inode_free()
+ * frees it again. You are allowed to use iget() and iput() to get references to
+ * the inode. But each drm_fs_inode_new() call must be paired with exactly one
+ * drm_fs_inode_free() call (which does not have to be the last iput()).
+ * We use drm_fs_inode_*() to manage our internal VFS mount-point and share it
+ * between multiple inode-users. You could, technically, call
+ * iget() + drm_fs_inode_free() directly after alloc and sometime later do an
+ * iput(), but this way you'd end up with a new vfsmount for each inode.
+ */
+
+static int drm_fs_cnt;
+static struct vfsmount *drm_fs_mnt;
+
+static const struct dentry_operations drm_fs_dops = {
+	.d_dname	= simple_dname,
+};
+
+static const struct super_operations drm_fs_sops = {
+	.statfs		= simple_statfs,
+};
+
+static struct dentry *drm_fs_mount(struct file_system_type *fs_type, int flags,
+				   const char *dev_name, void *data)
+{
+	return mount_pseudo(fs_type,
+			    "drm:",
+			    &drm_fs_sops,
+			    &drm_fs_dops,
+			    0x010203ff);
+}
+
+static struct file_system_type drm_fs_type = {
+	.name		= "drm",
+	.owner		= THIS_MODULE,
+	.mount		= drm_fs_mount,
+	.kill_sb	= kill_anon_super,
+};
+
+static struct inode *drm_fs_inode_new(void)
+{
+	struct inode *inode;
+	int r;
+
+	r = simple_pin_fs(&drm_fs_type, &drm_fs_mnt, &drm_fs_cnt);
+	if (r < 0) {
+		DRM_ERROR("Cannot mount pseudo fs: %d\n", r);
+		return ERR_PTR(r);
+	}
+
+	inode = alloc_anon_inode(drm_fs_mnt->mnt_sb);
+	if (IS_ERR(inode))
+		simple_release_fs(&drm_fs_mnt, &drm_fs_cnt);
+
+	return inode;
+}
+
+static void drm_fs_inode_free(struct inode *inode)
+{
+	if (inode) {
+		iput(inode);
+		simple_release_fs(&drm_fs_mnt, &drm_fs_cnt);
+	}
+}
+
+/**
+ * drm_dev_alloc - Allocate new DRM device
+ * @driver: DRM driver to allocate device for
+ * @parent: Parent device object
+ *
+ * Allocate and initialize a new DRM device. No device registration is done.
+ * Call drm_dev_register() to advertice the device to user space and register it
+ * with other core subsystems.
+ *
+ * The initial ref-count of the object is 1. Use drm_dev_ref() and
+ * drm_dev_unref() to take and drop further ref-counts.
+ *
+ * RETURNS:
+ * Pointer to new DRM device, or NULL if out of memory.
+ */
+struct drm_device *drm_dev_alloc(struct drm_driver *driver,
+				 struct device *parent)
+{
+	struct drm_device *dev;
+	int ret;
+
+	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+	if (!dev)
+		return NULL;
+
+	kref_init(&dev->ref);
+	dev->dev = parent;
+	dev->driver = driver;
+
+	INIT_LIST_HEAD(&dev->filelist);
+	INIT_LIST_HEAD(&dev->ctxlist);
+	INIT_LIST_HEAD(&dev->vmalist);
+	INIT_LIST_HEAD(&dev->maplist);
+	INIT_LIST_HEAD(&dev->vblank_event_list);
+
+	spin_lock_init(&dev->buf_lock);
+	spin_lock_init(&dev->event_lock);
+	mutex_init(&dev->struct_mutex);
+	mutex_init(&dev->ctxlist_mutex);
+	mutex_init(&dev->master_mutex);
+
+	dev->anon_inode = drm_fs_inode_new();
+	if (IS_ERR(dev->anon_inode)) {
+		ret = PTR_ERR(dev->anon_inode);
+		DRM_ERROR("Cannot allocate anonymous inode: %d\n", ret);
+		goto err_free;
+	}
+
+	if (drm_core_check_feature(dev, DRIVER_MODESET)) {
+		ret = drm_minor_alloc(dev, DRM_MINOR_CONTROL);
+		if (ret)
+			goto err_minors;
+	}
+
+	if (drm_core_check_feature(dev, DRIVER_RENDER)) {
+		ret = drm_minor_alloc(dev, DRM_MINOR_RENDER);
+		if (ret)
+			goto err_minors;
+	}
+
+	ret = drm_minor_alloc(dev, DRM_MINOR_LEGACY);
+	if (ret)
+		goto err_minors;
+
+	if (drm_ht_create(&dev->map_hash, 12))
+		goto err_minors;
+
+	ret = drm_legacy_ctxbitmap_init(dev);
+	if (ret) {
+		DRM_ERROR("Cannot allocate memory for context bitmap.\n");
+		goto err_ht;
+	}
+
+	if (driver->driver_features & DRIVER_GEM) {
+		ret = drm_gem_init(dev);
+		if (ret) {
+			DRM_ERROR("Cannot initialize graphics execution manager (GEM)\n");
+			goto err_ctxbitmap;
+		}
+	}
+
+	return dev;
+
+err_ctxbitmap:
+	drm_legacy_ctxbitmap_cleanup(dev);
+err_ht:
+	drm_ht_remove(&dev->map_hash);
+err_minors:
+	drm_minor_free(dev, DRM_MINOR_LEGACY);
+	drm_minor_free(dev, DRM_MINOR_RENDER);
+	drm_minor_free(dev, DRM_MINOR_CONTROL);
+	drm_fs_inode_free(dev->anon_inode);
+err_free:
+	mutex_destroy(&dev->master_mutex);
+	kfree(dev);
+	return NULL;
+}
+EXPORT_SYMBOL(drm_dev_alloc);
+
+static void drm_dev_release(struct kref *ref)
+{
+	struct drm_device *dev = container_of(ref, struct drm_device, ref);
+
+	if (dev->driver->driver_features & DRIVER_GEM)
+		drm_gem_destroy(dev);
+
+	drm_legacy_ctxbitmap_cleanup(dev);
+	drm_ht_remove(&dev->map_hash);
+	drm_fs_inode_free(dev->anon_inode);
+
+	drm_minor_free(dev, DRM_MINOR_LEGACY);
+	drm_minor_free(dev, DRM_MINOR_RENDER);
+	drm_minor_free(dev, DRM_MINOR_CONTROL);
+
+	mutex_destroy(&dev->master_mutex);
+	kfree(dev->unique);
+	kfree(dev);
+}
+
+/**
+ * drm_dev_ref - Take reference of a DRM device
+ * @dev: device to take reference of or NULL
+ *
+ * This increases the ref-count of @dev by one. You *must* already own a
+ * reference when calling this. Use drm_dev_unref() to drop this reference
+ * again.
+ *
+ * This function never fails. However, this function does not provide *any*
+ * guarantee whether the device is alive or running. It only provides a
+ * reference to the object and the memory associated with it.
+ */
+void drm_dev_ref(struct drm_device *dev)
+{
+	if (dev)
+		kref_get(&dev->ref);
+}
+EXPORT_SYMBOL(drm_dev_ref);
+
+/**
+ * drm_dev_unref - Drop reference of a DRM device
+ * @dev: device to drop reference of or NULL
+ *
+ * This decreases the ref-count of @dev by one. The device is destroyed if the
+ * ref-count drops to zero.
+ */
+void drm_dev_unref(struct drm_device *dev)
+{
+	if (dev)
+		kref_put(&dev->ref, drm_dev_release);
+}
+EXPORT_SYMBOL(drm_dev_unref);
+
+/**
+ * drm_dev_register - Register DRM device
+ * @dev: Device to register
+ * @flags: Flags passed to the driver's .load() function
+ *
+ * Register the DRM device @dev with the system, advertise device to user-space
+ * and start normal device operation. @dev must be allocated via drm_dev_alloc()
+ * previously.
+ *
+ * Never call this twice on any device!
+ *
+ * RETURNS:
+ * 0 on success, negative error code on failure.
+ */
+int drm_dev_register(struct drm_device *dev, unsigned long flags)
+{
+	int ret;
+
+	mutex_lock(&drm_global_mutex);
+
+	ret = drm_minor_register(dev, DRM_MINOR_CONTROL);
+	if (ret)
+		goto err_minors;
+
+	ret = drm_minor_register(dev, DRM_MINOR_RENDER);
+	if (ret)
+		goto err_minors;
+
+	ret = drm_minor_register(dev, DRM_MINOR_LEGACY);
+	if (ret)
+		goto err_minors;
+
+	if (dev->driver->load) {
+		ret = dev->driver->load(dev, flags);
+		if (ret)
+			goto err_minors;
+	}
+
+	/* setup grouping for legacy outputs */
+	if (drm_core_check_feature(dev, DRIVER_MODESET)) {
+		ret = drm_mode_group_init_legacy_group(dev,
+				&dev->primary->mode_group);
+		if (ret)
+			goto err_unload;
+	}
+
+	ret = 0;
+	goto out_unlock;
+
+err_unload:
+	if (dev->driver->unload)
+		dev->driver->unload(dev);
+err_minors:
+	drm_minor_unregister(dev, DRM_MINOR_LEGACY);
+	drm_minor_unregister(dev, DRM_MINOR_RENDER);
+	drm_minor_unregister(dev, DRM_MINOR_CONTROL);
+out_unlock:
+	mutex_unlock(&drm_global_mutex);
+	return ret;
+}
+EXPORT_SYMBOL(drm_dev_register);
+
+/**
+ * drm_dev_unregister - Unregister DRM device
+ * @dev: Device to unregister
+ *
+ * Unregister the DRM device from the system. This does the reverse of
+ * drm_dev_register() but does not deallocate the device. The caller must call
+ * drm_dev_unref() to drop their final reference.
+ */
+void drm_dev_unregister(struct drm_device *dev)
+{
+	struct drm_map_list *r_list, *list_temp;
+
+	drm_lastclose(dev);
+
+	if (dev->driver->unload)
+		dev->driver->unload(dev);
+
+	if (dev->agp)
+		drm_pci_agp_destroy(dev);
+
+	drm_vblank_cleanup(dev);
+
+	list_for_each_entry_safe(r_list, list_temp, &dev->maplist, head)
+		drm_rmmap(dev, r_list->map);
+
+	drm_minor_unregister(dev, DRM_MINOR_LEGACY);
+	drm_minor_unregister(dev, DRM_MINOR_RENDER);
+	drm_minor_unregister(dev, DRM_MINOR_CONTROL);
+}
+EXPORT_SYMBOL(drm_dev_unregister);
+
+/**
+ * drm_dev_set_unique - Set the unique name of a DRM device
+ * @dev: device of which to set the unique name
+ * @fmt: format string for unique name
+ *
+ * Sets the unique name of a DRM device using the specified format string and
+ * a variable list of arguments. Drivers can use this at driver probe time if
+ * the unique name of the devices they drive is static.
+ *
+ * Return: 0 on success or a negative error code on failure.
+ */
+int drm_dev_set_unique(struct drm_device *dev, const char *fmt, ...)
+{
+	va_list ap;
+
+	kfree(dev->unique);
+
+	va_start(ap, fmt);
+	dev->unique = kvasprintf(GFP_KERNEL, fmt, ap);
+	va_end(ap);
+
+	return dev->unique ? 0 : -ENOMEM;
+}
+EXPORT_SYMBOL(drm_dev_set_unique);
+
+/*
+ * DRM Core
+ * The DRM core module initializes all global DRM objects and makes them
+ * available to drivers. Once setup, drivers can probe their respective
+ * devices.
+ * Currently, core management includes:
+ *  - The "DRM-Global" key/value database
+ *  - Global ID management for connectors
+ *  - DRM major number allocation
+ *  - DRM minor management
+ *  - DRM sysfs class
+ *  - DRM debugfs root
+ *
+ * Furthermore, the DRM core provides dynamic char-dev lookups. For each
+ * interface registered on a DRM device, you can request minor numbers from DRM
+ * core. DRM core takes care of major-number management and char-dev
+ * registration. A stub ->open() callback forwards any open() requests to the
+ * registered minor.
+ */
+
+static int drm_stub_open(struct inode *inode, struct file *filp)
+{
+	const struct file_operations *new_fops;
+	struct drm_minor *minor;
+	int err;
+
+	DRM_DEBUG("\n");
+
+	mutex_lock(&drm_global_mutex);
+	minor = drm_minor_acquire(iminor(inode));
+	if (IS_ERR(minor)) {
+		err = PTR_ERR(minor);
+		goto out_unlock;
+	}
+
+	new_fops = fops_get(minor->dev->driver->fops);
+	if (!new_fops) {
+		err = -ENODEV;
+		goto out_release;
+	}
+
+	replace_fops(filp, new_fops);
+	if (filp->f_op->open)
+		err = filp->f_op->open(inode, filp);
+	else
+		err = 0;
+
+out_release:
+	drm_minor_release(minor);
+out_unlock:
+	mutex_unlock(&drm_global_mutex);
+	return err;
+}
+
+static const struct file_operations drm_stub_fops = {
+	.owner = THIS_MODULE,
+	.open = drm_stub_open,
+	.llseek = noop_llseek,
+};
+
+static int __init drm_core_init(void)
+{
+	int ret = -ENOMEM;
+
+	drm_global_init();
+	drm_connector_ida_init();
+	idr_init(&drm_minors_idr);
+
+	if (register_chrdev(DRM_MAJOR, "drm", &drm_stub_fops))
+		goto err_p1;
+
+	drm_class = drm_sysfs_create(THIS_MODULE, "drm");
+	if (IS_ERR(drm_class)) {
+		printk(KERN_ERR "DRM: Error creating drm class.\n");
+		ret = PTR_ERR(drm_class);
+		goto err_p2;
+	}
+
+	drm_debugfs_root = debugfs_create_dir("dri", NULL);
+	if (!drm_debugfs_root) {
+		DRM_ERROR("Cannot create /sys/kernel/debug/dri\n");
+		ret = -1;
+		goto err_p3;
+	}
+
+	DRM_INFO("Initialized %s %d.%d.%d %s\n",
+		 CORE_NAME, CORE_MAJOR, CORE_MINOR, CORE_PATCHLEVEL, CORE_DATE);
+	return 0;
+err_p3:
+	drm_sysfs_destroy();
+err_p2:
+	unregister_chrdev(DRM_MAJOR, "drm");
+
+	idr_destroy(&drm_minors_idr);
+err_p1:
+	return ret;
+}
+
+static void __exit drm_core_exit(void)
+{
+	debugfs_remove(drm_debugfs_root);
+	drm_sysfs_destroy();
+
+	unregister_chrdev(DRM_MAJOR, "drm");
+
+	drm_connector_ida_destroy();
+	idr_destroy(&drm_minors_idr);
+}
+
+module_init(drm_core_init);
+module_exit(drm_core_exit);