drivers/gpu/drm/drm_stub.c

   1 /**
   2  * \file drm_stub.h
   3  * Stub support
   4  *
   5  * \author Rickard E. (Rik) Faith <faith@valinux.com>
   6  */
   7
   8 /*
   9  * Created: Fri Jan 19 10:48:35 2001 by faith@acm.org
  10  *
  11  * Copyright 2001 VA Linux Systems, Inc., Sunnyvale, California.
  12  * All Rights Reserved.
  13  *
  14  * Permission is hereby granted, free of charge, to any person obtaining a
  15  * copy of this software and associated documentation files (the "Software"),
  16  * to deal in the Software without restriction, including without limitation
  17  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  18  * and/or sell copies of the Software, and to permit persons to whom the
  19  * Software is furnished to do so, subject to the following conditions:
  20  *
  21  * The above copyright notice and this permission notice (including the next
  22  * paragraph) shall be included in all copies or substantial portions of the
  23  * Software.
  24  *
  25  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  26  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  27  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  28  * PRECISION INSIGHT AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  29  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  30  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  31  * DEALINGS IN THE SOFTWARE.
  32  */
  33
  34 #include <linux/fs.h>
  35 #include <linux/module.h>
  36 #include <linux/moduleparam.h>
  37 #include <linux/mount.h>
  38 #include <linux/slab.h>
  39 #include <drm/drmP.h>
  40 #include <drm/drm_core.h>
  41
  42 unsigned int drm_debug = 0;     /* 1 to enable debug output */
  43 EXPORT_SYMBOL(drm_debug);
  44
  45 unsigned int drm_rnodes = 0;    /* 1 to enable experimental render nodes API */
  46 EXPORT_SYMBOL(drm_rnodes);
  47
  48 /* 1 to allow user space to request universal planes (experimental) */
  49 unsigned int drm_universal_planes = 0;
  50 EXPORT_SYMBOL(drm_universal_planes);
  51
  52 unsigned int drm_vblank_offdelay = 5000;    /* Default to 5000 msecs. */
  53 EXPORT_SYMBOL(drm_vblank_offdelay);
  54
  55 unsigned int drm_timestamp_precision = 20;  /* Default to 20 usecs. */
  56 EXPORT_SYMBOL(drm_timestamp_precision);
  57
  58 /*
  59  * Default to use monotonic timestamps for wait-for-vblank and page-flip
  60  * complete events.
  61  */
  62 unsigned int drm_timestamp_monotonic = 1;
  63
  64 MODULE_AUTHOR(CORE_AUTHOR);
  65 MODULE_DESCRIPTION(CORE_DESC);
  66 MODULE_LICENSE("GPL and additional rights");
  67 MODULE_PARM_DESC(debug, "Enable debug output");
  68 MODULE_PARM_DESC(rnodes, "Enable experimental render nodes API");
  69 MODULE_PARM_DESC(vblankoffdelay, "Delay until vblank irq auto-disable [msecs]");
  70 MODULE_PARM_DESC(timestamp_precision_usec, "Max. error on timestamps [usecs]");
  71 MODULE_PARM_DESC(timestamp_monotonic, "Use monotonic timestamps");
  72
  73 module_param_named(debug, drm_debug, int, 0600);
  74 module_param_named(rnodes, drm_rnodes, int, 0600);
  75 module_param_named(universal_planes, drm_universal_planes, int, 0600);
  76 module_param_named(vblankoffdelay, drm_vblank_offdelay, int, 0600);
  77 module_param_named(timestamp_precision_usec, drm_timestamp_precision, int, 0600);
  78 module_param_named(timestamp_monotonic, drm_timestamp_monotonic, int, 0600);
  79
  80 static DEFINE_SPINLOCK(drm_minor_lock);
  81 struct idr drm_minors_idr;
  82
  83 struct class *drm_class;
  84 struct dentry *drm_debugfs_root;
  85
  86 int drm_err(const char *func, const char *format, ...)
  87 {
  88         struct va_format vaf;
  89         va_list args;
  90         int r;
  91
  92         va_start(args, format);
  93
  94         vaf.fmt = format;
  95         vaf.va = &args;
  96
  97         r = printk(KERN_ERR "[" DRM_NAME ":%s] *ERROR* %pV", func, &vaf);
  98
  99         va_end(args);
 100
 101         return r;
 102 }
 103 EXPORT_SYMBOL(drm_err);
 104
 105 void drm_ut_debug_printk(const char *function_name, const char *format, ...)
 106 {
 107         struct va_format vaf;
 108         va_list args;
 109
 110         va_start(args, format);
 111         vaf.fmt = format;
 112         vaf.va = &args;
 113
 114         printk(KERN_DEBUG "[" DRM_NAME ":%s] %pV", function_name, &vaf);
 115
 116         va_end(args);
 117 }
 118 EXPORT_SYMBOL(drm_ut_debug_printk);
 119
 120 struct drm_master *drm_master_create(struct drm_minor *minor)
 121 {
 122         struct drm_master *master;
 123
 124         master = kzalloc(sizeof(*master), GFP_KERNEL);
 125         if (!master)
 126                 return NULL;
 127
 128         kref_init(&master->refcount);
 129         spin_lock_init(&master->lock.spinlock);
 130         init_waitqueue_head(&master->lock.lock_queue);
 131         drm_ht_create(&master->magiclist, DRM_MAGIC_HASH_ORDER);
 132         INIT_LIST_HEAD(&master->magicfree);
 133         master->minor = minor;
 134
 135         return master;
 136 }
 137
 138 struct drm_master *drm_master_get(struct drm_master *master)
 139 {
 140         kref_get(&master->refcount);
 141         return master;
 142 }
 143 EXPORT_SYMBOL(drm_master_get);
 144
 145 static void drm_master_destroy(struct kref *kref)
 146 {
 147         struct drm_master *master = container_of(kref, struct drm_master, refcount);
 148         struct drm_magic_entry *pt, *next;
 149         struct drm_device *dev = master->minor->dev;
 150         struct drm_map_list *r_list, *list_temp;
 151
 152         mutex_lock(&dev->struct_mutex);
 153         if (dev->driver->master_destroy)
 154                 dev->driver->master_destroy(dev, master);
 155
 156         list_for_each_entry_safe(r_list, list_temp, &dev->maplist, head) {
 157                 if (r_list->master == master) {
 158                         drm_rmmap_locked(dev, r_list->map);
 159                         r_list = NULL;
 160                 }
 161         }
 162
 163         if (master->unique) {
 164                 kfree(master->unique);
 165                 master->unique = NULL;
 166                 master->unique_len = 0;
 167         }
 168
 169         kfree(dev->devname);
 170         dev->devname = NULL;
 171
 172         list_for_each_entry_safe(pt, next, &master->magicfree, head) {
 173                 list_del(&pt->head);
 174                 drm_ht_remove_item(&master->magiclist, &pt->hash_item);
 175                 kfree(pt);
 176         }
 177
 178         drm_ht_remove(&master->magiclist);
 179
 180         mutex_unlock(&dev->struct_mutex);
 181         kfree(master);
 182 }
 183
 184 void drm_master_put(struct drm_master **master)
 185 {
 186         kref_put(&(*master)->refcount, drm_master_destroy);
 187         *master = NULL;
 188 }
 189 EXPORT_SYMBOL(drm_master_put);
 190
 191 int drm_setmaster_ioctl(struct drm_device *dev, void *data,
 192                         struct drm_file *file_priv)
 193 {
 194         int ret = 0;
 195
 196         mutex_lock(&dev->master_mutex);
 197         if (file_priv->is_master)
 198                 goto out_unlock;
 199
 200         if (file_priv->minor->master) {
 201                 ret = -EINVAL;
 202                 goto out_unlock;
 203         }
 204
 205         if (!file_priv->master) {
 206                 ret = -EINVAL;
 207                 goto out_unlock;
 208         }
 209
 210         file_priv->minor->master = drm_master_get(file_priv->master);
 211         file_priv->is_master = 1;
 212         if (dev->driver->master_set) {
 213                 ret = dev->driver->master_set(dev, file_priv, false);
 214                 if (unlikely(ret != 0)) {
 215                         file_priv->is_master = 0;
 216                         drm_master_put(&file_priv->minor->master);
 217                 }
 218         }
 219
 220 out_unlock:
 221         mutex_unlock(&dev->master_mutex);
 222         return ret;
 223 }
 224
 225 int drm_dropmaster_ioctl(struct drm_device *dev, void *data,
 226                          struct drm_file *file_priv)
 227 {
 228         int ret = -EINVAL;
 229
 230         mutex_lock(&dev->master_mutex);
 231         if (!file_priv->is_master)
 232                 goto out_unlock;
 233
 234         if (!file_priv->minor->master)
 235                 goto out_unlock;
 236
 237         ret = 0;
 238         if (dev->driver->master_drop)
 239                 dev->driver->master_drop(dev, file_priv, false);
 240         drm_master_put(&file_priv->minor->master);
 241         file_priv->is_master = 0;
 242
 243 out_unlock:
 244         mutex_unlock(&dev->master_mutex);
 245         return ret;
 246 }
 247
 248 /*
 249  * DRM Minors
 250  * A DRM device can provide several char-dev interfaces on the DRM-Major. Each
 251  * of them is represented by a drm_minor object. Depending on the capabilities
 252  * of the device-driver, different interfaces are registered.
 253  *
 254  * Minors can be accessed via dev->$minor_name. This pointer is either
 255  * NULL or a valid drm_minor pointer and stays valid as long as the device is
 256  * valid. This means, DRM minors have the same life-time as the underlying
 257  * device. However, this doesn't mean that the minor is active. Minors are
 258  * registered and unregistered dynamically according to device-state.
 259  */
 260
 261 static struct drm_minor **drm_minor_get_slot(struct drm_device *dev,
 262                                              unsigned int type)
 263 {
 264         switch (type) {
 265         case DRM_MINOR_LEGACY:
 266                 return &dev->primary;
 267         case DRM_MINOR_RENDER:
 268                 return &dev->render;
 269         case DRM_MINOR_CONTROL:
 270                 return &dev->control;
 271         default:
 272                 return NULL;
 273         }
 274 }
 275
 276 static int drm_minor_alloc(struct drm_device *dev, unsigned int type)
 277 {
 278         struct drm_minor *minor;
 279
 280         minor = kzalloc(sizeof(*minor), GFP_KERNEL);
 281         if (!minor)
 282                 return -ENOMEM;
 283
 284         minor->type = type;
 285         minor->dev = dev;
 286
 287         *drm_minor_get_slot(dev, type) = minor;
 288         return 0;
 289 }
 290
 291 static void drm_minor_free(struct drm_device *dev, unsigned int type)
 292 {
 293         struct drm_minor **slot;
 294
 295         slot = drm_minor_get_slot(dev, type);
 296         if (*slot) {
 297                 kfree(*slot);
 298                 *slot = NULL;
 299         }
 300 }
 301
 302 static int drm_minor_register(struct drm_device *dev, unsigned int type)
 303 {
 304         struct drm_minor *new_minor;
 305         unsigned long flags;
 306         int ret;
 307         int minor_id;
 308
 309         DRM_DEBUG("\n");
 310
 311         new_minor = *drm_minor_get_slot(dev, type);
 312         if (!new_minor)
 313                 return 0;
 314
 315         idr_preload(GFP_KERNEL);
 316         spin_lock_irqsave(&drm_minor_lock, flags);
 317         minor_id = idr_alloc(&drm_minors_idr,
 318                              NULL,
 319                              64 * type,
 320                              64 * (type + 1),
 321                              GFP_NOWAIT);
 322         spin_unlock_irqrestore(&drm_minor_lock, flags);
 323         idr_preload_end();
 324
 325         if (minor_id < 0)
 326                 return minor_id;
 327
 328         new_minor->index = minor_id;
 329
 330         ret = drm_debugfs_init(new_minor, minor_id, drm_debugfs_root);
 331         if (ret) {
 332                 DRM_ERROR("DRM: Failed to initialize /sys/kernel/debug/dri.\n");
 333                 goto err_id;
 334         }
 335
 336         ret = drm_sysfs_device_add(new_minor);
 337         if (ret) {
 338                 DRM_ERROR("DRM: Error sysfs_device_add.\n");
 339                 goto err_debugfs;
 340         }
 341
 342         /* replace NULL with @minor so lookups will succeed from now on */
 343         spin_lock_irqsave(&drm_minor_lock, flags);
 344         idr_replace(&drm_minors_idr, new_minor, new_minor->index);
 345         spin_unlock_irqrestore(&drm_minor_lock, flags);
 346
 347         DRM_DEBUG("new minor assigned %d\n", minor_id);
 348         return 0;
 349
 350 err_debugfs:
 351         drm_debugfs_cleanup(new_minor);
 352 err_id:
 353         spin_lock_irqsave(&drm_minor_lock, flags);
 354         idr_remove(&drm_minors_idr, minor_id);
 355         spin_unlock_irqrestore(&drm_minor_lock, flags);
 356         new_minor->index = 0;
 357         return ret;
 358 }
 359
 360 static void drm_minor_unregister(struct drm_device *dev, unsigned int type)
 361 {
 362         struct drm_minor *minor;
 363         unsigned long flags;
 364
 365         minor = *drm_minor_get_slot(dev, type);
 366         if (!minor || !minor->kdev)
 367                 return;
 368
 369         spin_lock_irqsave(&drm_minor_lock, flags);
 370         idr_remove(&drm_minors_idr, minor->index);
 371         spin_unlock_irqrestore(&drm_minor_lock, flags);
 372         minor->index = 0;
 373
 374         drm_debugfs_cleanup(minor);
 375         drm_sysfs_device_remove(minor);
 376 }
 377
 378 /**
 379  * drm_minor_acquire - Acquire a DRM minor
 380  * @minor_id: Minor ID of the DRM-minor
 381  *
 382  * Looks up the given minor-ID and returns the respective DRM-minor object. The
 383  * refence-count of the underlying device is increased so you must release this
 384  * object with drm_minor_release().
 385  *
 386  * As long as you hold this minor, it is guaranteed that the object and the
 387  * minor->dev pointer will stay valid! However, the device may get unplugged and
 388  * unregistered while you hold the minor.
 389  *
 390  * Returns:
 391  * Pointer to minor-object with increased device-refcount, or PTR_ERR on
 392  * failure.
 393  */
 394 struct drm_minor *drm_minor_acquire(unsigned int minor_id)
 395 {
 396         struct drm_minor *minor;
 397         unsigned long flags;
 398
 399         spin_lock_irqsave(&drm_minor_lock, flags);
 400         minor = idr_find(&drm_minors_idr, minor_id);
 401         if (minor)
 402                 drm_dev_ref(minor->dev);
 403         spin_unlock_irqrestore(&drm_minor_lock, flags);
 404
 405         if (!minor) {
 406                 return ERR_PTR(-ENODEV);
 407         } else if (drm_device_is_unplugged(minor->dev)) {
 408                 drm_dev_unref(minor->dev);
 409                 return ERR_PTR(-ENODEV);
 410         }
 411
 412         return minor;
 413 }
 414
 415 /**
 416  * drm_minor_release - Release DRM minor
 417  * @minor: Pointer to DRM minor object
 418  *
 419  * Release a minor that was previously acquired via drm_minor_acquire().
 420  */
 421 void drm_minor_release(struct drm_minor *minor)
 422 {
 423         drm_dev_unref(minor->dev);
 424 }
 425
 426 /**
 427  * Called via drm_exit() at module unload time or when pci device is
 428  * unplugged.
 429  *
 430  * Cleans up all DRM device, calling drm_lastclose().
 431  *
 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->count_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         kfree(dev->devname);
 652
 653         mutex_destroy(&dev->master_mutex);
 654         kfree(dev);
 655 }
 656
 657 /**
 658  * drm_dev_ref - Take reference of a DRM device
 659  * @dev: device to take reference of or NULL
 660  *
 661  * This increases the ref-count of @dev by one. You *must* already own a
 662  * reference when calling this. Use drm_dev_unref() to drop this reference
 663  * again.
 664  *
 665  * This function never fails. However, this function does not provide *any*
 666  * guarantee whether the device is alive or running. It only provides a
 667  * reference to the object and the memory associated with it.
 668  */
 669 void drm_dev_ref(struct drm_device *dev)
 670 {
 671         if (dev)
 672                 kref_get(&dev->ref);
 673 }
 674 EXPORT_SYMBOL(drm_dev_ref);
 675
 676 /**
 677  * drm_dev_unref - Drop reference of a DRM device
 678  * @dev: device to drop reference of or NULL
 679  *
 680  * This decreases the ref-count of @dev by one. The device is destroyed if the
 681  * ref-count drops to zero.
 682  */
 683 void drm_dev_unref(struct drm_device *dev)
 684 {
 685         if (dev)
 686                 kref_put(&dev->ref, drm_dev_release);
 687 }
 688 EXPORT_SYMBOL(drm_dev_unref);
 689
 690 /**
 691  * drm_dev_register - Register DRM device
 692  * @dev: Device to register
 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);