drivers/gpu/drm/drm_drv.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/debugfs.h>
  30 #include <linux/fs.h>
  31 #include <linux/module.h>
  32 #include <linux/moduleparam.h>
  33 #include <linux/mount.h>
  34 #include <linux/slab.h>
  35 #include <drm/drmP.h>
  36 #include <drm/drm_core.h>
  37 #include "drm_legacy.h"
  38 #include "drm_internal.h"
  39
  40 unsigned int drm_debug = 0;     /* 1 to enable debug output */
  41 EXPORT_SYMBOL(drm_debug);
  42
  43 MODULE_AUTHOR(CORE_AUTHOR);
  44 MODULE_DESCRIPTION(CORE_DESC);
  45 MODULE_LICENSE("GPL and additional rights");
  46 MODULE_PARM_DESC(debug, "Enable debug output");
  47 MODULE_PARM_DESC(vblankoffdelay, "Delay until vblank irq auto-disable [msecs] (0: never disable, <0: disable immediately)");
  48 MODULE_PARM_DESC(timestamp_precision_usec, "Max. error on timestamps [usecs]");
  49 MODULE_PARM_DESC(timestamp_monotonic, "Use monotonic timestamps");
  50
  51 module_param_named(debug, drm_debug, int, 0600);
  52
  53 static DEFINE_SPINLOCK(drm_minor_lock);
  54 static struct idr drm_minors_idr;
  55
  56 struct class *drm_class;
  57 static struct dentry *drm_debugfs_root;
  58
  59 int drm_err(const char *func, const char *format, ...)
  60 {
  61         struct va_format vaf;
  62         va_list args;
  63         int r;
  64
  65         va_start(args, format);
  66
  67         vaf.fmt = format;
  68         vaf.va = &args;
  69
  70         r = printk(KERN_ERR "[" DRM_NAME ":%s] *ERROR* %pV", func, &vaf);
  71
  72         va_end(args);
  73
  74         return r;
  75 }
  76 EXPORT_SYMBOL(drm_err);
  77
  78 void drm_ut_debug_printk(const char *function_name, const char *format, ...)
  79 {
  80         struct va_format vaf;
  81         va_list args;
  82
  83         va_start(args, format);
  84         vaf.fmt = format;
  85         vaf.va = &args;
  86
  87         printk(KERN_DEBUG "[" DRM_NAME ":%s] %pV", function_name, &vaf);
  88
  89         va_end(args);
  90 }
  91 EXPORT_SYMBOL(drm_ut_debug_printk);
  92
  93 struct drm_master *drm_master_create(struct drm_minor *minor)
  94 {
  95         struct drm_master *master;
  96
  97         master = kzalloc(sizeof(*master), GFP_KERNEL);
  98         if (!master)
  99                 return NULL;
 100
 101         kref_init(&master->refcount);
 102         spin_lock_init(&master->lock.spinlock);
 103         init_waitqueue_head(&master->lock.lock_queue);
 104         if (drm_ht_create(&master->magiclist, DRM_MAGIC_HASH_ORDER)) {
 105                 kfree(master);
 106                 return NULL;
 107         }
 108         INIT_LIST_HEAD(&master->magicfree);
 109         master->minor = minor;
 110
 111         return master;
 112 }
 113
 114 struct drm_master *drm_master_get(struct drm_master *master)
 115 {
 116         kref_get(&master->refcount);
 117         return master;
 118 }
 119 EXPORT_SYMBOL(drm_master_get);
 120
 121 static void drm_master_destroy(struct kref *kref)
 122 {
 123         struct drm_master *master = container_of(kref, struct drm_master, refcount);
 124         struct drm_device *dev = master->minor->dev;
 125         struct drm_map_list *r_list, *list_temp;
 126
 127         mutex_lock(&dev->struct_mutex);
 128         if (dev->driver->master_destroy)
 129                 dev->driver->master_destroy(dev, master);
 130
 131         list_for_each_entry_safe(r_list, list_temp, &dev->maplist, head) {
 132                 if (r_list->master == master) {
 133                         drm_legacy_rmmap_locked(dev, r_list->map);
 134                         r_list = NULL;
 135                 }
 136         }
 137
 138         if (master->unique) {
 139                 kfree(master->unique);
 140                 master->unique = NULL;
 141                 master->unique_len = 0;
 142         }
 143
 144         drm_ht_remove(&master->magiclist);
 145
 146         mutex_unlock(&dev->struct_mutex);
 147         kfree(master);
 148 }
 149
 150 void drm_master_put(struct drm_master **master)
 151 {
 152         kref_put(&(*master)->refcount, drm_master_destroy);
 153         *master = NULL;
 154 }
 155 EXPORT_SYMBOL(drm_master_put);
 156
 157 int drm_setmaster_ioctl(struct drm_device *dev, void *data,
 158                         struct drm_file *file_priv)
 159 {
 160         int ret = 0;
 161
 162         mutex_lock(&dev->master_mutex);
 163         if (file_priv->is_master)
 164                 goto out_unlock;
 165
 166         if (file_priv->minor->master) {
 167                 ret = -EINVAL;
 168                 goto out_unlock;
 169         }
 170
 171         if (!file_priv->master) {
 172                 ret = -EINVAL;
 173                 goto out_unlock;
 174         }
 175
 176         file_priv->minor->master = drm_master_get(file_priv->master);
 177         file_priv->is_master = 1;
 178         if (dev->driver->master_set) {
 179                 ret = dev->driver->master_set(dev, file_priv, false);
 180                 if (unlikely(ret != 0)) {
 181                         file_priv->is_master = 0;
 182                         drm_master_put(&file_priv->minor->master);
 183                 }
 184         }
 185
 186 out_unlock:
 187         mutex_unlock(&dev->master_mutex);
 188         return ret;
 189 }
 190
 191 int drm_dropmaster_ioctl(struct drm_device *dev, void *data,
 192                          struct drm_file *file_priv)
 193 {
 194         int ret = -EINVAL;
 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                 goto out_unlock;
 202
 203         ret = 0;
 204         if (dev->driver->master_drop)
 205                 dev->driver->master_drop(dev, file_priv, false);
 206         drm_master_put(&file_priv->minor->master);
 207         file_priv->is_master = 0;
 208
 209 out_unlock:
 210         mutex_unlock(&dev->master_mutex);
 211         return ret;
 212 }
 213
 214 /*
 215  * DRM Minors
 216  * A DRM device can provide several char-dev interfaces on the DRM-Major. Each
 217  * of them is represented by a drm_minor object. Depending on the capabilities
 218  * of the device-driver, different interfaces are registered.
 219  *
 220  * Minors can be accessed via dev->$minor_name. This pointer is either
 221  * NULL or a valid drm_minor pointer and stays valid as long as the device is
 222  * valid. This means, DRM minors have the same life-time as the underlying
 223  * device. However, this doesn't mean that the minor is active. Minors are
 224  * registered and unregistered dynamically according to device-state.
 225  */
 226
 227 static struct drm_minor **drm_minor_get_slot(struct drm_device *dev,
 228                                              unsigned int type)
 229 {
 230         switch (type) {
 231         case DRM_MINOR_LEGACY:
 232                 return &dev->primary;
 233         case DRM_MINOR_RENDER:
 234                 return &dev->render;
 235         case DRM_MINOR_CONTROL:
 236                 return &dev->control;
 237         default:
 238                 return NULL;
 239         }
 240 }
 241
 242 static int drm_minor_alloc(struct drm_device *dev, unsigned int type)
 243 {
 244         struct drm_minor *minor;
 245         unsigned long flags;
 246         int r;
 247
 248         minor = kzalloc(sizeof(*minor), GFP_KERNEL);
 249         if (!minor)
 250                 return -ENOMEM;
 251
 252         minor->type = type;
 253         minor->dev = dev;
 254
 255         idr_preload(GFP_KERNEL);
 256         spin_lock_irqsave(&drm_minor_lock, flags);
 257         r = idr_alloc(&drm_minors_idr,
 258                       NULL,
 259                       64 * type,
 260                       64 * (type + 1),
 261                       GFP_NOWAIT);
 262         spin_unlock_irqrestore(&drm_minor_lock, flags);
 263         idr_preload_end();
 264
 265         if (r < 0)
 266                 goto err_free;
 267
 268         minor->index = r;
 269
 270         minor->kdev = drm_sysfs_minor_alloc(minor);
 271         if (IS_ERR(minor->kdev)) {
 272                 r = PTR_ERR(minor->kdev);
 273                 goto err_index;
 274         }
 275
 276         *drm_minor_get_slot(dev, type) = minor;
 277         return 0;
 278
 279 err_index:
 280         spin_lock_irqsave(&drm_minor_lock, flags);
 281         idr_remove(&drm_minors_idr, minor->index);
 282         spin_unlock_irqrestore(&drm_minor_lock, flags);
 283 err_free:
 284         kfree(minor);
 285         return r;
 286 }
 287
 288 static void drm_minor_free(struct drm_device *dev, unsigned int type)
 289 {
 290         struct drm_minor **slot, *minor;
 291         unsigned long flags;
 292
 293         slot = drm_minor_get_slot(dev, type);
 294         minor = *slot;
 295         if (!minor)
 296                 return;
 297
 298         drm_mode_group_destroy(&minor->mode_group);
 299         put_device(minor->kdev);
 300
 301         spin_lock_irqsave(&drm_minor_lock, flags);
 302         idr_remove(&drm_minors_idr, minor->index);
 303         spin_unlock_irqrestore(&drm_minor_lock, flags);
 304
 305         kfree(minor);
 306         *slot = NULL;
 307 }
 308
 309 static int drm_minor_register(struct drm_device *dev, unsigned int type)
 310 {
 311         struct drm_minor *minor;
 312         unsigned long flags;
 313         int ret;
 314
 315         DRM_DEBUG("\n");
 316
 317         minor = *drm_minor_get_slot(dev, type);
 318         if (!minor)
 319                 return 0;
 320
 321         ret = drm_debugfs_init(minor, minor->index, drm_debugfs_root);
 322         if (ret) {
 323                 DRM_ERROR("DRM: Failed to initialize /sys/kernel/debug/dri.\n");
 324                 return ret;
 325         }
 326
 327         ret = device_add(minor->kdev);
 328         if (ret)
 329                 goto err_debugfs;
 330
 331         /* replace NULL with @minor so lookups will succeed from now on */
 332         spin_lock_irqsave(&drm_minor_lock, flags);
 333         idr_replace(&drm_minors_idr, minor, minor->index);
 334         spin_unlock_irqrestore(&drm_minor_lock, flags);
 335
 336         DRM_DEBUG("new minor registered %d\n", minor->index);
 337         return 0;
 338
 339 err_debugfs:
 340         drm_debugfs_cleanup(minor);
 341         return ret;
 342 }
 343
 344 static void drm_minor_unregister(struct drm_device *dev, unsigned int type)
 345 {
 346         struct drm_minor *minor;
 347         unsigned long flags;
 348
 349         minor = *drm_minor_get_slot(dev, type);
 350         if (!minor || !device_is_registered(minor->kdev))
 351                 return;
 352
 353         /* replace @minor with NULL so lookups will fail from now on */
 354         spin_lock_irqsave(&drm_minor_lock, flags);
 355         idr_replace(&drm_minors_idr, NULL, minor->index);
 356         spin_unlock_irqrestore(&drm_minor_lock, flags);
 357
 358         device_del(minor->kdev);
 359         dev_set_drvdata(minor->kdev, NULL); /* safety belt */
 360         drm_debugfs_cleanup(minor);
 361 }
 362
 363 /**
 364  * drm_minor_acquire - Acquire a DRM minor
 365  * @minor_id: Minor ID of the DRM-minor
 366  *
 367  * Looks up the given minor-ID and returns the respective DRM-minor object. The
 368  * refence-count of the underlying device is increased so you must release this
 369  * object with drm_minor_release().
 370  *
 371  * As long as you hold this minor, it is guaranteed that the object and the
 372  * minor->dev pointer will stay valid! However, the device may get unplugged and
 373  * unregistered while you hold the minor.
 374  *
 375  * Returns:
 376  * Pointer to minor-object with increased device-refcount, or PTR_ERR on
 377  * failure.
 378  */
 379 struct drm_minor *drm_minor_acquire(unsigned int minor_id)
 380 {
 381         struct drm_minor *minor;
 382         unsigned long flags;
 383
 384         spin_lock_irqsave(&drm_minor_lock, flags);
 385         minor = idr_find(&drm_minors_idr, minor_id);
 386         if (minor)
 387                 drm_dev_ref(minor->dev);
 388         spin_unlock_irqrestore(&drm_minor_lock, flags);
 389
 390         if (!minor) {
 391                 return ERR_PTR(-ENODEV);
 392         } else if (drm_device_is_unplugged(minor->dev)) {
 393                 drm_dev_unref(minor->dev);
 394                 return ERR_PTR(-ENODEV);
 395         }
 396
 397         return minor;
 398 }
 399
 400 /**
 401  * drm_minor_release - Release DRM minor
 402  * @minor: Pointer to DRM minor object
 403  *
 404  * Release a minor that was previously acquired via drm_minor_acquire().
 405  */
 406 void drm_minor_release(struct drm_minor *minor)
 407 {
 408         drm_dev_unref(minor->dev);
 409 }
 410
 411 /**
 412  * drm_put_dev - Unregister and release a DRM device
 413  * @dev: DRM device
 414  *
 415  * Called at module unload time or when a PCI device is unplugged.
 416  *
 417  * Use of this function is discouraged. It will eventually go away completely.
 418  * Please use drm_dev_unregister() and drm_dev_unref() explicitly instead.
 419  *
 420  * Cleans up all DRM device, calling drm_lastclose().
 421  */
 422 void drm_put_dev(struct drm_device *dev)
 423 {
 424         DRM_DEBUG("\n");
 425
 426         if (!dev) {
 427                 DRM_ERROR("cleanup called no dev\n");
 428                 return;
 429         }
 430
 431         drm_dev_unregister(dev);
 432         drm_dev_unref(dev);
 433 }
 434 EXPORT_SYMBOL(drm_put_dev);
 435
 436 void drm_unplug_dev(struct drm_device *dev)
 437 {
 438         /* for a USB device */
 439         drm_minor_unregister(dev, DRM_MINOR_LEGACY);
 440         drm_minor_unregister(dev, DRM_MINOR_RENDER);
 441         drm_minor_unregister(dev, DRM_MINOR_CONTROL);
 442
 443         mutex_lock(&drm_global_mutex);
 444
 445         drm_device_set_unplugged(dev);
 446
 447         if (dev->open_count == 0) {
 448                 drm_put_dev(dev);
 449         }
 450         mutex_unlock(&drm_global_mutex);
 451 }
 452 EXPORT_SYMBOL(drm_unplug_dev);
 453
 454 /*
 455  * DRM internal mount
 456  * We want to be able to allocate our own "struct address_space" to control
 457  * memory-mappings in VRAM (or stolen RAM, ...). However, core MM does not allow
 458  * stand-alone address_space objects, so we need an underlying inode. As there
 459  * is no way to allocate an independent inode easily, we need a fake internal
 460  * VFS mount-point.
 461  *
 462  * The drm_fs_inode_new() function allocates a new inode, drm_fs_inode_free()
 463  * frees it again. You are allowed to use iget() and iput() to get references to
 464  * the inode. But each drm_fs_inode_new() call must be paired with exactly one
 465  * drm_fs_inode_free() call (which does not have to be the last iput()).
 466  * We use drm_fs_inode_*() to manage our internal VFS mount-point and share it
 467  * between multiple inode-users. You could, technically, call
 468  * iget() + drm_fs_inode_free() directly after alloc and sometime later do an
 469  * iput(), but this way you'd end up with a new vfsmount for each inode.
 470  */
 471
 472 static int drm_fs_cnt;
 473 static struct vfsmount *drm_fs_mnt;
 474
 475 static const struct dentry_operations drm_fs_dops = {
 476         .d_dname        = simple_dname,
 477 };
 478
 479 static const struct super_operations drm_fs_sops = {
 480         .statfs         = simple_statfs,
 481 };
 482
 483 static struct dentry *drm_fs_mount(struct file_system_type *fs_type, int flags,
 484                                    const char *dev_name, void *data)
 485 {
 486         return mount_pseudo(fs_type,
 487                             "drm:",
 488                             &drm_fs_sops,
 489                             &drm_fs_dops,
 490                             0x010203ff);
 491 }
 492
 493 static struct file_system_type drm_fs_type = {
 494         .name           = "drm",
 495         .owner          = THIS_MODULE,
 496         .mount          = drm_fs_mount,
 497         .kill_sb        = kill_anon_super,
 498 };
 499
 500 static struct inode *drm_fs_inode_new(void)
 501 {
 502         struct inode *inode;
 503         int r;
 504
 505         r = simple_pin_fs(&drm_fs_type, &drm_fs_mnt, &drm_fs_cnt);
 506         if (r < 0) {
 507                 DRM_ERROR("Cannot mount pseudo fs: %d\n", r);
 508                 return ERR_PTR(r);
 509         }
 510
 511         inode = alloc_anon_inode(drm_fs_mnt->mnt_sb);
 512         if (IS_ERR(inode))
 513                 simple_release_fs(&drm_fs_mnt, &drm_fs_cnt);
 514
 515         return inode;
 516 }
 517
 518 static void drm_fs_inode_free(struct inode *inode)
 519 {
 520         if (inode) {
 521                 iput(inode);
 522                 simple_release_fs(&drm_fs_mnt, &drm_fs_cnt);
 523         }
 524 }
 525
 526 /**
 527  * drm_dev_alloc - Allocate new DRM device
 528  * @driver: DRM driver to allocate device for
 529  * @parent: Parent device object
 530  *
 531  * Allocate and initialize a new DRM device. No device registration is done.
 532  * Call drm_dev_register() to advertice the device to user space and register it
 533  * with other core subsystems.
 534  *
 535  * The initial ref-count of the object is 1. Use drm_dev_ref() and
 536  * drm_dev_unref() to take and drop further ref-counts.
 537  *
 538  * RETURNS:
 539  * Pointer to new DRM device, or NULL if out of memory.
 540  */
 541 struct drm_device *drm_dev_alloc(struct drm_driver *driver,
 542                                  struct device *parent)
 543 {
 544         struct drm_device *dev;
 545         int ret;
 546
 547         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 548         if (!dev)
 549                 return NULL;
 550
 551         kref_init(&dev->ref);
 552         dev->dev = parent;
 553         dev->driver = driver;
 554
 555         INIT_LIST_HEAD(&dev->filelist);
 556         INIT_LIST_HEAD(&dev->ctxlist);
 557         INIT_LIST_HEAD(&dev->vmalist);
 558         INIT_LIST_HEAD(&dev->maplist);
 559         INIT_LIST_HEAD(&dev->vblank_event_list);
 560
 561         spin_lock_init(&dev->buf_lock);
 562         spin_lock_init(&dev->event_lock);
 563         mutex_init(&dev->struct_mutex);
 564         mutex_init(&dev->ctxlist_mutex);
 565         mutex_init(&dev->master_mutex);
 566
 567         dev->anon_inode = drm_fs_inode_new();
 568         if (IS_ERR(dev->anon_inode)) {
 569                 ret = PTR_ERR(dev->anon_inode);
 570                 DRM_ERROR("Cannot allocate anonymous inode: %d\n", ret);
 571                 goto err_free;
 572         }
 573
 574         if (drm_core_check_feature(dev, DRIVER_MODESET)) {
 575                 ret = drm_minor_alloc(dev, DRM_MINOR_CONTROL);
 576                 if (ret)
 577                         goto err_minors;
 578         }
 579
 580         if (drm_core_check_feature(dev, DRIVER_RENDER)) {
 581                 ret = drm_minor_alloc(dev, DRM_MINOR_RENDER);
 582                 if (ret)
 583                         goto err_minors;
 584         }
 585
 586         ret = drm_minor_alloc(dev, DRM_MINOR_LEGACY);
 587         if (ret)
 588                 goto err_minors;
 589
 590         if (drm_ht_create(&dev->map_hash, 12))
 591                 goto err_minors;
 592
 593         ret = drm_legacy_ctxbitmap_init(dev);
 594         if (ret) {
 595                 DRM_ERROR("Cannot allocate memory for context bitmap.\n");
 596                 goto err_ht;
 597         }
 598
 599         if (driver->driver_features & DRIVER_GEM) {
 600                 ret = drm_gem_init(dev);
 601                 if (ret) {
 602                         DRM_ERROR("Cannot initialize graphics execution manager (GEM)\n");
 603                         goto err_ctxbitmap;
 604                 }
 605         }
 606
 607         return dev;
 608
 609 err_ctxbitmap:
 610         drm_legacy_ctxbitmap_cleanup(dev);
 611 err_ht:
 612         drm_ht_remove(&dev->map_hash);
 613 err_minors:
 614         drm_minor_free(dev, DRM_MINOR_LEGACY);
 615         drm_minor_free(dev, DRM_MINOR_RENDER);
 616         drm_minor_free(dev, DRM_MINOR_CONTROL);
 617         drm_fs_inode_free(dev->anon_inode);
 618 err_free:
 619         mutex_destroy(&dev->master_mutex);
 620         kfree(dev);
 621         return NULL;
 622 }
 623 EXPORT_SYMBOL(drm_dev_alloc);
 624
 625 static void drm_dev_release(struct kref *ref)
 626 {
 627         struct drm_device *dev = container_of(ref, struct drm_device, ref);
 628
 629         if (dev->driver->driver_features & DRIVER_GEM)
 630                 drm_gem_destroy(dev);
 631
 632         drm_legacy_ctxbitmap_cleanup(dev);
 633         drm_ht_remove(&dev->map_hash);
 634         drm_fs_inode_free(dev->anon_inode);
 635
 636         drm_minor_free(dev, DRM_MINOR_LEGACY);
 637         drm_minor_free(dev, DRM_MINOR_RENDER);
 638         drm_minor_free(dev, DRM_MINOR_CONTROL);
 639
 640         mutex_destroy(&dev->master_mutex);
 641         kfree(dev->unique);
 642         kfree(dev);
 643 }
 644
 645 /**
 646  * drm_dev_ref - Take reference of a DRM device
 647  * @dev: device to take reference of or NULL
 648  *
 649  * This increases the ref-count of @dev by one. You *must* already own a
 650  * reference when calling this. Use drm_dev_unref() to drop this reference
 651  * again.
 652  *
 653  * This function never fails. However, this function does not provide *any*
 654  * guarantee whether the device is alive or running. It only provides a
 655  * reference to the object and the memory associated with it.
 656  */
 657 void drm_dev_ref(struct drm_device *dev)
 658 {
 659         if (dev)
 660                 kref_get(&dev->ref);
 661 }
 662 EXPORT_SYMBOL(drm_dev_ref);
 663
 664 /**
 665  * drm_dev_unref - Drop reference of a DRM device
 666  * @dev: device to drop reference of or NULL
 667  *
 668  * This decreases the ref-count of @dev by one. The device is destroyed if the
 669  * ref-count drops to zero.
 670  */
 671 void drm_dev_unref(struct drm_device *dev)
 672 {
 673         if (dev)
 674                 kref_put(&dev->ref, drm_dev_release);
 675 }
 676 EXPORT_SYMBOL(drm_dev_unref);
 677
 678 /**
 679  * drm_dev_register - Register DRM device
 680  * @dev: Device to register
 681  * @flags: Flags passed to the driver's .load() function
 682  *
 683  * Register the DRM device @dev with the system, advertise device to user-space
 684  * and start normal device operation. @dev must be allocated via drm_dev_alloc()
 685  * previously.
 686  *
 687  * Never call this twice on any device!
 688  *
 689  * RETURNS:
 690  * 0 on success, negative error code on failure.
 691  */
 692 int drm_dev_register(struct drm_device *dev, unsigned long flags)
 693 {
 694         int ret;
 695
 696         mutex_lock(&drm_global_mutex);
 697
 698         ret = drm_minor_register(dev, DRM_MINOR_CONTROL);
 699         if (ret)
 700                 goto err_minors;
 701
 702         ret = drm_minor_register(dev, DRM_MINOR_RENDER);
 703         if (ret)
 704                 goto err_minors;
 705
 706         ret = drm_minor_register(dev, DRM_MINOR_LEGACY);
 707         if (ret)
 708                 goto err_minors;
 709
 710         if (dev->driver->load) {
 711                 ret = dev->driver->load(dev, flags);
 712                 if (ret)
 713                         goto err_minors;
 714         }
 715
 716         /* setup grouping for legacy outputs */
 717         if (drm_core_check_feature(dev, DRIVER_MODESET)) {
 718                 ret = drm_mode_group_init_legacy_group(dev,
 719                                 &dev->primary->mode_group);
 720                 if (ret)
 721                         goto err_unload;
 722         }
 723
 724         ret = 0;
 725         goto out_unlock;
 726
 727 err_unload:
 728         if (dev->driver->unload)
 729                 dev->driver->unload(dev);
 730 err_minors:
 731         drm_minor_unregister(dev, DRM_MINOR_LEGACY);
 732         drm_minor_unregister(dev, DRM_MINOR_RENDER);
 733         drm_minor_unregister(dev, DRM_MINOR_CONTROL);
 734 out_unlock:
 735         mutex_unlock(&drm_global_mutex);
 736         return ret;
 737 }
 738 EXPORT_SYMBOL(drm_dev_register);
 739
 740 /**
 741  * drm_dev_unregister - Unregister DRM device
 742  * @dev: Device to unregister
 743  *
 744  * Unregister the DRM device from the system. This does the reverse of
 745  * drm_dev_register() but does not deallocate the device. The caller must call
 746  * drm_dev_unref() to drop their final reference.
 747  */
 748 void drm_dev_unregister(struct drm_device *dev)
 749 {
 750         struct drm_map_list *r_list, *list_temp;
 751
 752         drm_lastclose(dev);
 753
 754         if (dev->driver->unload)
 755                 dev->driver->unload(dev);
 756
 757         if (dev->agp)
 758                 drm_pci_agp_destroy(dev);
 759
 760         drm_vblank_cleanup(dev);
 761
 762         list_for_each_entry_safe(r_list, list_temp, &dev->maplist, head)
 763                 drm_legacy_rmmap(dev, r_list->map);
 764
 765         drm_minor_unregister(dev, DRM_MINOR_LEGACY);
 766         drm_minor_unregister(dev, DRM_MINOR_RENDER);
 767         drm_minor_unregister(dev, DRM_MINOR_CONTROL);
 768 }
 769 EXPORT_SYMBOL(drm_dev_unregister);
 770
 771 /**
 772  * drm_dev_set_unique - Set the unique name of a DRM device
 773  * @dev: device of which to set the unique name
 774  * @fmt: format string for unique name
 775  *
 776  * Sets the unique name of a DRM device using the specified format string and
 777  * a variable list of arguments. Drivers can use this at driver probe time if
 778  * the unique name of the devices they drive is static.
 779  *
 780  * Return: 0 on success or a negative error code on failure.
 781  */
 782 int drm_dev_set_unique(struct drm_device *dev, const char *fmt, ...)
 783 {
 784         va_list ap;
 785
 786         kfree(dev->unique);
 787
 788         va_start(ap, fmt);
 789         dev->unique = kvasprintf(GFP_KERNEL, fmt, ap);
 790         va_end(ap);
 791
 792         return dev->unique ? 0 : -ENOMEM;
 793 }
 794 EXPORT_SYMBOL(drm_dev_set_unique);
 795
 796 /*
 797  * DRM Core
 798  * The DRM core module initializes all global DRM objects and makes them
 799  * available to drivers. Once setup, drivers can probe their respective
 800  * devices.
 801  * Currently, core management includes:
 802  *  - The "DRM-Global" key/value database
 803  *  - Global ID management for connectors
 804  *  - DRM major number allocation
 805  *  - DRM minor management
 806  *  - DRM sysfs class
 807  *  - DRM debugfs root
 808  *
 809  * Furthermore, the DRM core provides dynamic char-dev lookups. For each
 810  * interface registered on a DRM device, you can request minor numbers from DRM
 811  * core. DRM core takes care of major-number management and char-dev
 812  * registration. A stub ->open() callback forwards any open() requests to the
 813  * registered minor.
 814  */
 815
 816 static int drm_stub_open(struct inode *inode, struct file *filp)
 817 {
 818         const struct file_operations *new_fops;
 819         struct drm_minor *minor;
 820         int err;
 821
 822         DRM_DEBUG("\n");
 823
 824         mutex_lock(&drm_global_mutex);
 825         minor = drm_minor_acquire(iminor(inode));
 826         if (IS_ERR(minor)) {
 827                 err = PTR_ERR(minor);
 828                 goto out_unlock;
 829         }
 830
 831         new_fops = fops_get(minor->dev->driver->fops);
 832         if (!new_fops) {
 833                 err = -ENODEV;
 834                 goto out_release;
 835         }
 836
 837         replace_fops(filp, new_fops);
 838         if (filp->f_op->open)
 839                 err = filp->f_op->open(inode, filp);
 840         else
 841                 err = 0;
 842
 843 out_release:
 844         drm_minor_release(minor);
 845 out_unlock:
 846         mutex_unlock(&drm_global_mutex);
 847         return err;
 848 }
 849
 850 static const struct file_operations drm_stub_fops = {
 851         .owner = THIS_MODULE,
 852         .open = drm_stub_open,
 853         .llseek = noop_llseek,
 854 };
 855
 856 static int __init drm_core_init(void)
 857 {
 858         int ret = -ENOMEM;
 859
 860         drm_global_init();
 861         drm_connector_ida_init();
 862         idr_init(&drm_minors_idr);
 863
 864         if (register_chrdev(DRM_MAJOR, "drm", &drm_stub_fops))
 865                 goto err_p1;
 866
 867         drm_class = drm_sysfs_create(THIS_MODULE, "drm");
 868         if (IS_ERR(drm_class)) {
 869                 printk(KERN_ERR "DRM: Error creating drm class.\n");
 870                 ret = PTR_ERR(drm_class);
 871                 goto err_p2;
 872         }
 873
 874         drm_debugfs_root = debugfs_create_dir("dri", NULL);
 875         if (!drm_debugfs_root) {
 876                 DRM_ERROR("Cannot create /sys/kernel/debug/dri\n");
 877                 ret = -1;
 878                 goto err_p3;
 879         }
 880
 881         DRM_INFO("Initialized %s %d.%d.%d %s\n",
 882                  CORE_NAME, CORE_MAJOR, CORE_MINOR, CORE_PATCHLEVEL, CORE_DATE);
 883         return 0;
 884 err_p3:
 885         drm_sysfs_destroy();
 886 err_p2:
 887         unregister_chrdev(DRM_MAJOR, "drm");
 888
 889         idr_destroy(&drm_minors_idr);
 890 err_p1:
 891         return ret;
 892 }
 893
 894 static void __exit drm_core_exit(void)
 895 {
 896         debugfs_remove(drm_debugfs_root);
 897         drm_sysfs_destroy();
 898
 899         unregister_chrdev(DRM_MAJOR, "drm");
 900
 901         drm_connector_ida_destroy();
 902         idr_destroy(&drm_minors_idr);
 903 }
 904
 905 module_init(drm_core_init);
 906 module_exit(drm_core_exit);