drivers/gpu/drm/drm_stub.c

   1 /*
   2  * Created: Fri Jan 19 10:48:35 2001 by faith@acm.org
   3  *
   4  * Copyright 2001 VA Linux Systems, Inc., Sunnyvale, California.
   5  * All Rights Reserved.
   6  *
   7  * Author Rickard E. (Rik) Faith <faith@valinux.com>
   8  *
   9  * Permission is hereby granted, free of charge, to any person obtaining a
  10  * copy of this software and associated documentation files (the "Software"),
  11  * to deal in the Software without restriction, including without limitation
  12  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  13  * and/or sell copies of the Software, and to permit persons to whom the
  14  * Software is furnished to do so, subject to the following conditions:
  15  *
  16  * The above copyright notice and this permission notice (including the next
  17  * paragraph) shall be included in all copies or substantial portions of the
  18  * Software.
  19  *
  20  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  21  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  23  * PRECISION INSIGHT AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  24  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  25  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  26  * DEALINGS IN THE SOFTWARE.
  27  */
  28
  29 #include <linux/fs.h>
  30 #include <linux/module.h>
  31 #include <linux/moduleparam.h>
  32 #include <linux/mount.h>
  33 #include <linux/slab.h>
  34 #include <drm/drmP.h>
  35 #include <drm/drm_core.h>
  36
  37 unsigned int drm_debug = 0;     /* 1 to enable debug output */
  38 EXPORT_SYMBOL(drm_debug);
  39
  40 unsigned int drm_rnodes = 0;    /* 1 to enable experimental render nodes API */
  41 EXPORT_SYMBOL(drm_rnodes);
  42
  43 /* 1 to allow user space to request universal planes (experimental) */
  44 unsigned int drm_universal_planes = 0;
  45 EXPORT_SYMBOL(drm_universal_planes);
  46
  47 unsigned int drm_vblank_offdelay = 5000;    /* Default to 5000 msecs. */
  48 EXPORT_SYMBOL(drm_vblank_offdelay);
  49
  50 unsigned int drm_timestamp_precision = 20;  /* Default to 20 usecs. */
  51 EXPORT_SYMBOL(drm_timestamp_precision);
  52
  53 /*
  54  * Default to use monotonic timestamps for wait-for-vblank and page-flip
  55  * complete events.
  56  */
  57 unsigned int drm_timestamp_monotonic = 1;
  58
  59 MODULE_AUTHOR(CORE_AUTHOR);
  60 MODULE_DESCRIPTION(CORE_DESC);
  61 MODULE_LICENSE("GPL and additional rights");
  62 MODULE_PARM_DESC(debug, "Enable debug output");
  63 MODULE_PARM_DESC(rnodes, "Enable experimental render nodes API");
  64 MODULE_PARM_DESC(vblankoffdelay, "Delay until vblank irq auto-disable [msecs]");
  65 MODULE_PARM_DESC(timestamp_precision_usec, "Max. error on timestamps [usecs]");
  66 MODULE_PARM_DESC(timestamp_monotonic, "Use monotonic timestamps");
  67
  68 module_param_named(debug, drm_debug, int, 0600);
  69 module_param_named(rnodes, drm_rnodes, int, 0600);
  70 module_param_named(universal_planes, drm_universal_planes, int, 0600);
  71 module_param_named(vblankoffdelay, drm_vblank_offdelay, int, 0600);
  72 module_param_named(timestamp_precision_usec, drm_timestamp_precision, int, 0600);
  73 module_param_named(timestamp_monotonic, drm_timestamp_monotonic, int, 0600);
  74
  75 static DEFINE_SPINLOCK(drm_minor_lock);
  76 struct idr drm_minors_idr;
  77
  78 struct class *drm_class;
  79 struct dentry *drm_debugfs_root;
  80
  81 int drm_err(const char *func, const char *format, ...)
  82 {
  83         struct va_format vaf;
  84         va_list args;
  85         int r;
  86
  87         va_start(args, format);
  88
  89         vaf.fmt = format;
  90         vaf.va = &args;
  91
  92         r = printk(KERN_ERR "[" DRM_NAME ":%s] *ERROR* %pV", func, &vaf);
  93
  94         va_end(args);
  95
  96         return r;
  97 }
  98 EXPORT_SYMBOL(drm_err);
  99
 100 void drm_ut_debug_printk(const char *function_name, const char *format, ...)
 101 {
 102         struct va_format vaf;
 103         va_list args;
 104
 105         va_start(args, format);
 106         vaf.fmt = format;
 107         vaf.va = &args;
 108
 109         printk(KERN_DEBUG "[" DRM_NAME ":%s] %pV", function_name, &vaf);
 110
 111         va_end(args);
 112 }
 113 EXPORT_SYMBOL(drm_ut_debug_printk);
 114
 115 struct drm_master *drm_master_create(struct drm_minor *minor)
 116 {
 117         struct drm_master *master;
 118
 119         master = kzalloc(sizeof(*master), GFP_KERNEL);
 120         if (!master)
 121                 return NULL;
 122
 123         kref_init(&master->refcount);
 124         spin_lock_init(&master->lock.spinlock);
 125         init_waitqueue_head(&master->lock.lock_queue);
 126         if (drm_ht_create(&master->magiclist, DRM_MAGIC_HASH_ORDER)) {
 127                 kfree(master);
 128                 return NULL;
 129         }
 130         INIT_LIST_HEAD(&master->magicfree);
 131         master->minor = minor;
 132
 133         return master;
 134 }
 135
 136 struct drm_master *drm_master_get(struct drm_master *master)
 137 {
 138         kref_get(&master->refcount);
 139         return master;
 140 }
 141 EXPORT_SYMBOL(drm_master_get);
 142
 143 static void drm_master_destroy(struct kref *kref)
 144 {
 145         struct drm_master *master = container_of(kref, struct drm_master, refcount);
 146         struct drm_magic_entry *pt, *next;
 147         struct drm_device *dev = master->minor->dev;
 148         struct drm_map_list *r_list, *list_temp;
 149
 150         mutex_lock(&dev->struct_mutex);
 151         if (dev->driver->master_destroy)
 152                 dev->driver->master_destroy(dev, master);
 153
 154         list_for_each_entry_safe(r_list, list_temp, &dev->maplist, head) {
 155                 if (r_list->master == master) {
 156                         drm_rmmap_locked(dev, r_list->map);
 157                         r_list = NULL;
 158                 }
 159         }
 160
 161         if (master->unique) {
 162                 kfree(master->unique);
 163                 master->unique = NULL;
 164                 master->unique_len = 0;
 165         }
 166
 167         list_for_each_entry_safe(pt, next, &master->magicfree, head) {
 168                 list_del(&pt->head);
 169                 drm_ht_remove_item(&master->magiclist, &pt->hash_item);
 170                 kfree(pt);
 171         }
 172
 173         drm_ht_remove(&master->magiclist);
 174
 175         mutex_unlock(&dev->struct_mutex);
 176         kfree(master);
 177 }
 178
 179 void drm_master_put(struct drm_master **master)
 180 {
 181         kref_put(&(*master)->refcount, drm_master_destroy);
 182         *master = NULL;
 183 }
 184 EXPORT_SYMBOL(drm_master_put);
 185
 186 int drm_setmaster_ioctl(struct drm_device *dev, void *data,
 187                         struct drm_file *file_priv)
 188 {
 189         int ret = 0;
 190
 191         mutex_lock(&dev->master_mutex);
 192         if (file_priv->is_master)
 193                 goto out_unlock;
 194
 195         if (file_priv->minor->master) {
 196                 ret = -EINVAL;
 197                 goto out_unlock;
 198         }
 199
 200         if (!file_priv->master) {
 201                 ret = -EINVAL;
 202                 goto out_unlock;
 203         }
 204
 205         file_priv->minor->master = drm_master_get(file_priv->master);
 206         file_priv->is_master = 1;
 207         if (dev->driver->master_set) {
 208                 ret = dev->driver->master_set(dev, file_priv, false);
 209                 if (unlikely(ret != 0)) {
 210                         file_priv->is_master = 0;
 211                         drm_master_put(&file_priv->minor->master);
 212                 }
 213         }
 214
 215 out_unlock:
 216         mutex_unlock(&dev->master_mutex);
 217         return ret;
 218 }
 219
 220 int drm_dropmaster_ioctl(struct drm_device *dev, void *data,
 221                          struct drm_file *file_priv)
 222 {
 223         int ret = -EINVAL;
 224
 225         mutex_lock(&dev->master_mutex);
 226         if (!file_priv->is_master)
 227                 goto out_unlock;
 228
 229         if (!file_priv->minor->master)
 230                 goto out_unlock;
 231
 232         ret = 0;
 233         if (dev->driver->master_drop)
 234                 dev->driver->master_drop(dev, file_priv, false);
 235         drm_master_put(&file_priv->minor->master);
 236         file_priv->is_master = 0;
 237
 238 out_unlock:
 239         mutex_unlock(&dev->master_mutex);
 240         return ret;
 241 }
 242
 243 /*
 244  * DRM Minors
 245  * A DRM device can provide several char-dev interfaces on the DRM-Major. Each
 246  * of them is represented by a drm_minor object. Depending on the capabilities
 247  * of the device-driver, different interfaces are registered.
 248  *
 249  * Minors can be accessed via dev->$minor_name. This pointer is either
 250  * NULL or a valid drm_minor pointer and stays valid as long as the device is
 251  * valid. This means, DRM minors have the same life-time as the underlying
 252  * device. However, this doesn't mean that the minor is active. Minors are
 253  * registered and unregistered dynamically according to device-state.
 254  */
 255
 256 static struct drm_minor **drm_minor_get_slot(struct drm_device *dev,
 257                                              unsigned int type)
 258 {
 259         switch (type) {
 260         case DRM_MINOR_LEGACY:
 261                 return &dev->primary;
 262         case DRM_MINOR_RENDER:
 263                 return &dev->render;
 264         case DRM_MINOR_CONTROL:
 265                 return &dev->control;
 266         default:
 267                 return NULL;
 268         }
 269 }
 270
 271 static int drm_minor_alloc(struct drm_device *dev, unsigned int type)
 272 {
 273         struct drm_minor *minor;
 274
 275         minor = kzalloc(sizeof(*minor), GFP_KERNEL);
 276         if (!minor)
 277                 return -ENOMEM;
 278
 279         minor->type = type;
 280         minor->dev = dev;
 281
 282         *drm_minor_get_slot(dev, type) = minor;
 283         return 0;
 284 }
 285
 286 static void drm_minor_free(struct drm_device *dev, unsigned int type)
 287 {
 288         struct drm_minor **slot;
 289
 290         slot = drm_minor_get_slot(dev, type);
 291         if (*slot) {
 292                 drm_mode_group_destroy(&(*slot)->mode_group);
 293                 kfree(*slot);
 294                 *slot = NULL;
 295         }
 296 }
 297
 298 static int drm_minor_register(struct drm_device *dev, unsigned int type)
 299 {
 300         struct drm_minor *new_minor;
 301         unsigned long flags;
 302         int ret;
 303         int minor_id;
 304
 305         DRM_DEBUG("\n");
 306
 307         new_minor = *drm_minor_get_slot(dev, type);
 308         if (!new_minor)
 309                 return 0;
 310
 311         idr_preload(GFP_KERNEL);
 312         spin_lock_irqsave(&drm_minor_lock, flags);
 313         minor_id = idr_alloc(&drm_minors_idr,
 314                              NULL,
 315                              64 * type,
 316                              64 * (type + 1),
 317                              GFP_NOWAIT);
 318         spin_unlock_irqrestore(&drm_minor_lock, flags);
 319         idr_preload_end();
 320
 321         if (minor_id < 0)
 322                 return minor_id;
 323
 324         new_minor->index = minor_id;
 325
 326         ret = drm_debugfs_init(new_minor, minor_id, drm_debugfs_root);
 327         if (ret) {
 328                 DRM_ERROR("DRM: Failed to initialize /sys/kernel/debug/dri.\n");
 329                 goto err_id;
 330         }
 331
 332         ret = drm_sysfs_device_add(new_minor);
 333         if (ret) {
 334                 DRM_ERROR("DRM: Error sysfs_device_add.\n");
 335                 goto err_debugfs;
 336         }
 337
 338         /* replace NULL with @minor so lookups will succeed from now on */
 339         spin_lock_irqsave(&drm_minor_lock, flags);
 340         idr_replace(&drm_minors_idr, new_minor, new_minor->index);
 341         spin_unlock_irqrestore(&drm_minor_lock, flags);
 342
 343         DRM_DEBUG("new minor assigned %d\n", minor_id);
 344         return 0;
 345
 346 err_debugfs:
 347         drm_debugfs_cleanup(new_minor);
 348 err_id:
 349         spin_lock_irqsave(&drm_minor_lock, flags);
 350         idr_remove(&drm_minors_idr, minor_id);
 351         spin_unlock_irqrestore(&drm_minor_lock, flags);
 352         new_minor->index = 0;
 353         return ret;
 354 }
 355
 356 static void drm_minor_unregister(struct drm_device *dev, unsigned int type)
 357 {
 358         struct drm_minor *minor;
 359         unsigned long flags;
 360
 361         minor = *drm_minor_get_slot(dev, type);
 362         if (!minor || !minor->kdev)
 363                 return;
 364
 365         spin_lock_irqsave(&drm_minor_lock, flags);
 366         idr_remove(&drm_minors_idr, minor->index);
 367         spin_unlock_irqrestore(&drm_minor_lock, flags);
 368         minor->index = 0;
 369
 370         drm_debugfs_cleanup(minor);
 371         drm_sysfs_device_remove(minor);
 372 }
 373
 374 /**
 375  * drm_minor_acquire - Acquire a DRM minor
 376  * @minor_id: Minor ID of the DRM-minor
 377  *
 378  * Looks up the given minor-ID and returns the respective DRM-minor object. The
 379  * refence-count of the underlying device is increased so you must release this
 380  * object with drm_minor_release().
 381  *
 382  * As long as you hold this minor, it is guaranteed that the object and the
 383  * minor->dev pointer will stay valid! However, the device may get unplugged and
 384  * unregistered while you hold the minor.
 385  *
 386  * Returns:
 387  * Pointer to minor-object with increased device-refcount, or PTR_ERR on
 388  * failure.
 389  */
 390 struct drm_minor *drm_minor_acquire(unsigned int minor_id)
 391 {
 392         struct drm_minor *minor;
 393         unsigned long flags;
 394
 395         spin_lock_irqsave(&drm_minor_lock, flags);
 396         minor = idr_find(&drm_minors_idr, minor_id);
 397         if (minor)
 398                 drm_dev_ref(minor->dev);
 399         spin_unlock_irqrestore(&drm_minor_lock, flags);
 400
 401         if (!minor) {
 402                 return ERR_PTR(-ENODEV);
 403         } else if (drm_device_is_unplugged(minor->dev)) {
 404                 drm_dev_unref(minor->dev);
 405                 return ERR_PTR(-ENODEV);
 406         }
 407
 408         return minor;
 409 }
 410
 411 /**
 412  * drm_minor_release - Release DRM minor
 413  * @minor: Pointer to DRM minor object
 414  *
 415  * Release a minor that was previously acquired via drm_minor_acquire().
 416  */
 417 void drm_minor_release(struct drm_minor *minor)
 418 {
 419         drm_dev_unref(minor->dev);
 420 }
 421
 422 /**
 423  * drm_put_dev - Unregister and release a DRM device
 424  * @dev: DRM device
 425  *
 426  * Called at module unload time or when a PCI device is unplugged.
 427  *
 428  * Use of this function is discouraged. It will eventually go away completely.
 429  * Please use drm_dev_unregister() and drm_dev_unref() explicitly instead.
 430  *
 431  * Cleans up all DRM device, calling drm_lastclose().
 432  */
 433 void drm_put_dev(struct drm_device *dev)
 434 {
 435         DRM_DEBUG("\n");
 436
 437         if (!dev) {
 438                 DRM_ERROR("cleanup called no dev\n");
 439                 return;
 440         }
 441
 442         drm_dev_unregister(dev);
 443         drm_dev_unref(dev);
 444 }
 445 EXPORT_SYMBOL(drm_put_dev);
 446
 447 void drm_unplug_dev(struct drm_device *dev)
 448 {
 449         /* for a USB device */
 450         drm_minor_unregister(dev, DRM_MINOR_LEGACY);
 451         drm_minor_unregister(dev, DRM_MINOR_RENDER);
 452         drm_minor_unregister(dev, DRM_MINOR_CONTROL);
 453
 454         mutex_lock(&drm_global_mutex);
 455
 456         drm_device_set_unplugged(dev);
 457
 458         if (dev->open_count == 0) {
 459                 drm_put_dev(dev);
 460         }
 461         mutex_unlock(&drm_global_mutex);
 462 }
 463 EXPORT_SYMBOL(drm_unplug_dev);
 464
 465 /*
 466  * DRM internal mount
 467  * We want to be able to allocate our own "struct address_space" to control
 468  * memory-mappings in VRAM (or stolen RAM, ...). However, core MM does not allow
 469  * stand-alone address_space objects, so we need an underlying inode. As there
 470  * is no way to allocate an independent inode easily, we need a fake internal
 471  * VFS mount-point.
 472  *
 473  * The drm_fs_inode_new() function allocates a new inode, drm_fs_inode_free()
 474  * frees it again. You are allowed to use iget() and iput() to get references to
 475  * the inode. But each drm_fs_inode_new() call must be paired with exactly one
 476  * drm_fs_inode_free() call (which does not have to be the last iput()).
 477  * We use drm_fs_inode_*() to manage our internal VFS mount-point and share it
 478  * between multiple inode-users. You could, technically, call
 479  * iget() + drm_fs_inode_free() directly after alloc and sometime later do an
 480  * iput(), but this way you'd end up with a new vfsmount for each inode.
 481  */
 482
 483 static int drm_fs_cnt;
 484 static struct vfsmount *drm_fs_mnt;
 485
 486 static const struct dentry_operations drm_fs_dops = {
 487         .d_dname        = simple_dname,
 488 };
 489
 490 static const struct super_operations drm_fs_sops = {
 491         .statfs         = simple_statfs,
 492 };
 493
 494 static struct dentry *drm_fs_mount(struct file_system_type *fs_type, int flags,
 495                                    const char *dev_name, void *data)
 496 {
 497         return mount_pseudo(fs_type,
 498                             "drm:",
 499                             &drm_fs_sops,
 500                             &drm_fs_dops,
 501                             0x010203ff);
 502 }
 503
 504 static struct file_system_type drm_fs_type = {
 505         .name           = "drm",
 506         .owner          = THIS_MODULE,
 507         .mount          = drm_fs_mount,
 508         .kill_sb        = kill_anon_super,
 509 };
 510
 511 static struct inode *drm_fs_inode_new(void)
 512 {
 513         struct inode *inode;
 514         int r;
 515
 516         r = simple_pin_fs(&drm_fs_type, &drm_fs_mnt, &drm_fs_cnt);
 517         if (r < 0) {
 518                 DRM_ERROR("Cannot mount pseudo fs: %d\n", r);
 519                 return ERR_PTR(r);
 520         }
 521
 522         inode = alloc_anon_inode(drm_fs_mnt->mnt_sb);
 523         if (IS_ERR(inode))
 524                 simple_release_fs(&drm_fs_mnt, &drm_fs_cnt);
 525
 526         return inode;
 527 }
 528
 529 static void drm_fs_inode_free(struct inode *inode)
 530 {
 531         if (inode) {
 532                 iput(inode);
 533                 simple_release_fs(&drm_fs_mnt, &drm_fs_cnt);
 534         }
 535 }
 536
 537 /**
 538  * drm_dev_alloc - Allocate new DRM device
 539  * @driver: DRM driver to allocate device for
 540  * @parent: Parent device object
 541  *
 542  * Allocate and initialize a new DRM device. No device registration is done.
 543  * Call drm_dev_register() to advertice the device to user space and register it
 544  * with other core subsystems.
 545  *
 546  * The initial ref-count of the object is 1. Use drm_dev_ref() and
 547  * drm_dev_unref() to take and drop further ref-counts.
 548  *
 549  * RETURNS:
 550  * Pointer to new DRM device, or NULL if out of memory.
 551  */
 552 struct drm_device *drm_dev_alloc(struct drm_driver *driver,
 553                                  struct device *parent)
 554 {
 555         struct drm_device *dev;
 556         int ret;
 557
 558         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 559         if (!dev)
 560                 return NULL;
 561
 562         kref_init(&dev->ref);
 563         dev->dev = parent;
 564         dev->driver = driver;
 565
 566         INIT_LIST_HEAD(&dev->filelist);
 567         INIT_LIST_HEAD(&dev->ctxlist);
 568         INIT_LIST_HEAD(&dev->vmalist);
 569         INIT_LIST_HEAD(&dev->maplist);
 570         INIT_LIST_HEAD(&dev->vblank_event_list);
 571
 572         spin_lock_init(&dev->buf_lock);
 573         spin_lock_init(&dev->event_lock);
 574         mutex_init(&dev->struct_mutex);
 575         mutex_init(&dev->ctxlist_mutex);
 576         mutex_init(&dev->master_mutex);
 577
 578         dev->anon_inode = drm_fs_inode_new();
 579         if (IS_ERR(dev->anon_inode)) {
 580                 ret = PTR_ERR(dev->anon_inode);
 581                 DRM_ERROR("Cannot allocate anonymous inode: %d\n", ret);
 582                 goto err_free;
 583         }
 584
 585         if (drm_core_check_feature(dev, DRIVER_MODESET)) {
 586                 ret = drm_minor_alloc(dev, DRM_MINOR_CONTROL);
 587                 if (ret)
 588                         goto err_minors;
 589         }
 590
 591         if (drm_core_check_feature(dev, DRIVER_RENDER) && drm_rnodes) {
 592                 ret = drm_minor_alloc(dev, DRM_MINOR_RENDER);
 593                 if (ret)
 594                         goto err_minors;
 595         }
 596
 597         ret = drm_minor_alloc(dev, DRM_MINOR_LEGACY);
 598         if (ret)
 599                 goto err_minors;
 600
 601         if (drm_ht_create(&dev->map_hash, 12))
 602                 goto err_minors;
 603
 604         ret = drm_ctxbitmap_init(dev);
 605         if (ret) {
 606                 DRM_ERROR("Cannot allocate memory for context bitmap.\n");
 607                 goto err_ht;
 608         }
 609
 610         if (driver->driver_features & DRIVER_GEM) {
 611                 ret = drm_gem_init(dev);
 612                 if (ret) {
 613                         DRM_ERROR("Cannot initialize graphics execution manager (GEM)\n");
 614                         goto err_ctxbitmap;
 615                 }
 616         }
 617
 618         return dev;
 619
 620 err_ctxbitmap:
 621         drm_ctxbitmap_cleanup(dev);
 622 err_ht:
 623         drm_ht_remove(&dev->map_hash);
 624 err_minors:
 625         drm_minor_free(dev, DRM_MINOR_LEGACY);
 626         drm_minor_free(dev, DRM_MINOR_RENDER);
 627         drm_minor_free(dev, DRM_MINOR_CONTROL);
 628         drm_fs_inode_free(dev->anon_inode);
 629 err_free:
 630         mutex_destroy(&dev->master_mutex);
 631         kfree(dev);
 632         return NULL;
 633 }
 634 EXPORT_SYMBOL(drm_dev_alloc);
 635
 636 static void drm_dev_release(struct kref *ref)
 637 {
 638         struct drm_device *dev = container_of(ref, struct drm_device, ref);
 639
 640         if (dev->driver->driver_features & DRIVER_GEM)
 641                 drm_gem_destroy(dev);
 642
 643         drm_ctxbitmap_cleanup(dev);
 644         drm_ht_remove(&dev->map_hash);
 645         drm_fs_inode_free(dev->anon_inode);
 646
 647         drm_minor_free(dev, DRM_MINOR_LEGACY);
 648         drm_minor_free(dev, DRM_MINOR_RENDER);
 649         drm_minor_free(dev, DRM_MINOR_CONTROL);
 650
 651         mutex_destroy(&dev->master_mutex);
 652         kfree(dev->unique);
 653         kfree(dev);
 654 }
 655
 656 /**
 657  * drm_dev_ref - Take reference of a DRM device
 658  * @dev: device to take reference of or NULL
 659  *
 660  * This increases the ref-count of @dev by one. You *must* already own a
 661  * reference when calling this. Use drm_dev_unref() to drop this reference
 662  * again.
 663  *
 664  * This function never fails. However, this function does not provide *any*
 665  * guarantee whether the device is alive or running. It only provides a
 666  * reference to the object and the memory associated with it.
 667  */
 668 void drm_dev_ref(struct drm_device *dev)
 669 {
 670         if (dev)
 671                 kref_get(&dev->ref);
 672 }
 673 EXPORT_SYMBOL(drm_dev_ref);
 674
 675 /**
 676  * drm_dev_unref - Drop reference of a DRM device
 677  * @dev: device to drop reference of or NULL
 678  *
 679  * This decreases the ref-count of @dev by one. The device is destroyed if the
 680  * ref-count drops to zero.
 681  */
 682 void drm_dev_unref(struct drm_device *dev)
 683 {
 684         if (dev)
 685                 kref_put(&dev->ref, drm_dev_release);
 686 }
 687 EXPORT_SYMBOL(drm_dev_unref);
 688
 689 /**
 690  * drm_dev_register - Register DRM device
 691  * @dev: Device to register
 692  * @flags: Flags passed to the driver's .load() function
 693  *
 694  * Register the DRM device @dev with the system, advertise device to user-space
 695  * and start normal device operation. @dev must be allocated via drm_dev_alloc()
 696  * previously.
 697  *
 698  * Never call this twice on any device!
 699  *
 700  * RETURNS:
 701  * 0 on success, negative error code on failure.
 702  */
 703 int drm_dev_register(struct drm_device *dev, unsigned long flags)
 704 {
 705         int ret;
 706
 707         mutex_lock(&drm_global_mutex);
 708
 709         ret = drm_minor_register(dev, DRM_MINOR_CONTROL);
 710         if (ret)
 711                 goto err_minors;
 712
 713         ret = drm_minor_register(dev, DRM_MINOR_RENDER);
 714         if (ret)
 715                 goto err_minors;
 716
 717         ret = drm_minor_register(dev, DRM_MINOR_LEGACY);
 718         if (ret)
 719                 goto err_minors;
 720
 721         if (dev->driver->load) {
 722                 ret = dev->driver->load(dev, flags);
 723                 if (ret)
 724                         goto err_minors;
 725         }
 726
 727         /* setup grouping for legacy outputs */
 728         if (drm_core_check_feature(dev, DRIVER_MODESET)) {
 729                 ret = drm_mode_group_init_legacy_group(dev,
 730                                 &dev->primary->mode_group);
 731                 if (ret)
 732                         goto err_unload;
 733         }
 734
 735         ret = 0;
 736         goto out_unlock;
 737
 738 err_unload:
 739         if (dev->driver->unload)
 740                 dev->driver->unload(dev);
 741 err_minors:
 742         drm_minor_unregister(dev, DRM_MINOR_LEGACY);
 743         drm_minor_unregister(dev, DRM_MINOR_RENDER);
 744         drm_minor_unregister(dev, DRM_MINOR_CONTROL);
 745 out_unlock:
 746         mutex_unlock(&drm_global_mutex);
 747         return ret;
 748 }
 749 EXPORT_SYMBOL(drm_dev_register);
 750
 751 /**
 752  * drm_dev_unregister - Unregister DRM device
 753  * @dev: Device to unregister
 754  *
 755  * Unregister the DRM device from the system. This does the reverse of
 756  * drm_dev_register() but does not deallocate the device. The caller must call
 757  * drm_dev_unref() to drop their final reference.
 758  */
 759 void drm_dev_unregister(struct drm_device *dev)
 760 {
 761         struct drm_map_list *r_list, *list_temp;
 762
 763         drm_lastclose(dev);
 764
 765         if (dev->driver->unload)
 766                 dev->driver->unload(dev);
 767
 768         if (dev->agp)
 769                 drm_pci_agp_destroy(dev);
 770
 771         drm_vblank_cleanup(dev);
 772
 773         list_for_each_entry_safe(r_list, list_temp, &dev->maplist, head)
 774                 drm_rmmap(dev, r_list->map);
 775
 776         drm_minor_unregister(dev, DRM_MINOR_LEGACY);
 777         drm_minor_unregister(dev, DRM_MINOR_RENDER);
 778         drm_minor_unregister(dev, DRM_MINOR_CONTROL);
 779 }
 780 EXPORT_SYMBOL(drm_dev_unregister);
 781
 782 /**
 783  * drm_dev_set_unique - Set the unique name of a DRM device
 784  * @dev: device of which to set the unique name
 785  * @fmt: format string for unique name
 786  *
 787  * Sets the unique name of a DRM device using the specified format string and
 788  * a variable list of arguments. Drivers can use this at driver probe time if
 789  * the unique name of the devices they drive is static.
 790  *
 791  * Return: 0 on success or a negative error code on failure.
 792  */
 793 int drm_dev_set_unique(struct drm_device *dev, const char *fmt, ...)
 794 {
 795         va_list ap;
 796
 797         kfree(dev->unique);
 798
 799         va_start(ap, fmt);
 800         dev->unique = kvasprintf(GFP_KERNEL, fmt, ap);
 801         va_end(ap);
 802
 803         return dev->unique ? 0 : -ENOMEM;
 804 }
 805 EXPORT_SYMBOL(drm_dev_set_unique);