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 void drm_err(const char *func, const char *format, ...)
  60 {
  61         struct va_format vaf;
  62         va_list args;
  63
  64         va_start(args, format);
  65
  66         vaf.fmt = format;
  67         vaf.va = &args;
  68
  69         printk(KERN_ERR "[" DRM_NAME ":%s] *ERROR* %pV", func, &vaf);
  70
  71         va_end(args);
  72 }
  73 EXPORT_SYMBOL(drm_err);
  74
  75 void drm_ut_debug_printk(const char *function_name, const char *format, ...)
  76 {
  77         struct va_format vaf;
  78         va_list args;
  79
  80         va_start(args, format);
  81         vaf.fmt = format;
  82         vaf.va = &args;
  83
  84         printk(KERN_DEBUG "[" DRM_NAME ":%s] %pV", function_name, &vaf);
  85
  86         va_end(args);
  87 }
  88 EXPORT_SYMBOL(drm_ut_debug_printk);
  89
  90 #define DRM_MAGIC_HASH_ORDER  4  /**< Size of key hash table. Must be power of 2. */
  91
  92 struct drm_master *drm_master_create(struct drm_minor *minor)
  93 {
  94         struct drm_master *master;
  95
  96         master = kzalloc(sizeof(*master), GFP_KERNEL);
  97         if (!master)
  98                 return NULL;
  99
 100         kref_init(&master->refcount);
 101         spin_lock_init(&master->lock.spinlock);
 102         init_waitqueue_head(&master->lock.lock_queue);
 103         if (drm_ht_create(&master->magiclist, DRM_MAGIC_HASH_ORDER)) {
 104                 kfree(master);
 105                 return NULL;
 106         }
 107         INIT_LIST_HEAD(&master->magicfree);
 108         master->minor = minor;
 109
 110         return master;
 111 }
 112
 113 struct drm_master *drm_master_get(struct drm_master *master)
 114 {
 115         kref_get(&master->refcount);
 116         return master;
 117 }
 118 EXPORT_SYMBOL(drm_master_get);
 119
 120 static void drm_master_destroy(struct kref *kref)
 121 {
 122         struct drm_master *master = container_of(kref, struct drm_master, refcount);
 123         struct drm_device *dev = master->minor->dev;
 124         struct drm_map_list *r_list, *list_temp;
 125
 126         mutex_lock(&dev->struct_mutex);
 127         if (dev->driver->master_destroy)
 128                 dev->driver->master_destroy(dev, master);
 129
 130         list_for_each_entry_safe(r_list, list_temp, &dev->maplist, head) {
 131                 if (r_list->master == master) {
 132                         drm_legacy_rmmap_locked(dev, r_list->map);
 133                         r_list = NULL;
 134                 }
 135         }
 136
 137         if (master->unique) {
 138                 kfree(master->unique);
 139                 master->unique = NULL;
 140                 master->unique_len = 0;
 141         }
 142
 143         drm_ht_remove(&master->magiclist);
 144
 145         mutex_unlock(&dev->struct_mutex);
 146         kfree(master);
 147 }
 148
 149 void drm_master_put(struct drm_master **master)
 150 {
 151         kref_put(&(*master)->refcount, drm_master_destroy);
 152         *master = NULL;
 153 }
 154 EXPORT_SYMBOL(drm_master_put);
 155
 156 int drm_setmaster_ioctl(struct drm_device *dev, void *data,
 157                         struct drm_file *file_priv)
 158 {
 159         int ret = 0;
 160
 161         mutex_lock(&dev->master_mutex);
 162         if (file_priv->is_master)
 163                 goto out_unlock;
 164
 165         if (file_priv->minor->master) {
 166                 ret = -EINVAL;
 167                 goto out_unlock;
 168         }
 169
 170         if (!file_priv->master) {
 171                 ret = -EINVAL;
 172                 goto out_unlock;
 173         }
 174
 175         file_priv->minor->master = drm_master_get(file_priv->master);
 176         file_priv->is_master = 1;
 177         if (dev->driver->master_set) {
 178                 ret = dev->driver->master_set(dev, file_priv, false);
 179                 if (unlikely(ret != 0)) {
 180                         file_priv->is_master = 0;
 181                         drm_master_put(&file_priv->minor->master);
 182                 }
 183         }
 184
 185 out_unlock:
 186         mutex_unlock(&dev->master_mutex);
 187         return ret;
 188 }
 189
 190 int drm_dropmaster_ioctl(struct drm_device *dev, void *data,
 191                          struct drm_file *file_priv)
 192 {
 193         int ret = -EINVAL;
 194
 195         mutex_lock(&dev->master_mutex);
 196         if (!file_priv->is_master)
 197                 goto out_unlock;
 198
 199         if (!file_priv->minor->master)
 200                 goto out_unlock;
 201
 202         ret = 0;
 203         if (dev->driver->master_drop)
 204                 dev->driver->master_drop(dev, file_priv, false);
 205         drm_master_put(&file_priv->minor->master);
 206         file_priv->is_master = 0;
 207
 208 out_unlock:
 209         mutex_unlock(&dev->master_mutex);
 210         return ret;
 211 }
 212
 213 /*
 214  * DRM Minors
 215  * A DRM device can provide several char-dev interfaces on the DRM-Major. Each
 216  * of them is represented by a drm_minor object. Depending on the capabilities
 217  * of the device-driver, different interfaces are registered.
 218  *
 219  * Minors can be accessed via dev->$minor_name. This pointer is either
 220  * NULL or a valid drm_minor pointer and stays valid as long as the device is
 221  * valid. This means, DRM minors have the same life-time as the underlying
 222  * device. However, this doesn't mean that the minor is active. Minors are
 223  * registered and unregistered dynamically according to device-state.
 224  */
 225
 226 static struct drm_minor **drm_minor_get_slot(struct drm_device *dev,
 227                                              unsigned int type)
 228 {
 229         switch (type) {
 230         case DRM_MINOR_LEGACY:
 231                 return &dev->primary;
 232         case DRM_MINOR_RENDER:
 233                 return &dev->render;
 234         case DRM_MINOR_CONTROL:
 235                 return &dev->control;
 236         default:
 237                 return NULL;
 238         }
 239 }
 240
 241 static int drm_minor_alloc(struct drm_device *dev, unsigned int type)
 242 {
 243         struct drm_minor *minor;
 244         unsigned long flags;
 245         int r;
 246
 247         minor = kzalloc(sizeof(*minor), GFP_KERNEL);
 248         if (!minor)
 249                 return -ENOMEM;
 250
 251         minor->type = type;
 252         minor->dev = dev;
 253
 254         idr_preload(GFP_KERNEL);
 255         spin_lock_irqsave(&drm_minor_lock, flags);
 256         r = idr_alloc(&drm_minors_idr,
 257                       NULL,
 258                       64 * type,
 259                       64 * (type + 1),
 260                       GFP_NOWAIT);
 261         spin_unlock_irqrestore(&drm_minor_lock, flags);
 262         idr_preload_end();
 263
 264         if (r < 0)
 265                 goto err_free;
 266
 267         minor->index = r;
 268
 269         minor->kdev = drm_sysfs_minor_alloc(minor);
 270         if (IS_ERR(minor->kdev)) {
 271                 r = PTR_ERR(minor->kdev);
 272                 goto err_index;
 273         }
 274
 275         *drm_minor_get_slot(dev, type) = minor;
 276         return 0;
 277
 278 err_index:
 279         spin_lock_irqsave(&drm_minor_lock, flags);
 280         idr_remove(&drm_minors_idr, minor->index);
 281         spin_unlock_irqrestore(&drm_minor_lock, flags);
 282 err_free:
 283         kfree(minor);
 284         return r;
 285 }
 286
 287 static void drm_minor_free(struct drm_device *dev, unsigned int type)
 288 {
 289         struct drm_minor **slot, *minor;
 290         unsigned long flags;
 291
 292         slot = drm_minor_get_slot(dev, type);
 293         minor = *slot;
 294         if (!minor)
 295                 return;
 296
 297         drm_mode_group_destroy(&minor->mode_group);
 298         put_device(minor->kdev);
 299
 300         spin_lock_irqsave(&drm_minor_lock, flags);
 301         idr_remove(&drm_minors_idr, minor->index);
 302         spin_unlock_irqrestore(&drm_minor_lock, flags);
 303
 304         kfree(minor);
 305         *slot = NULL;
 306 }
 307
 308 static int drm_minor_register(struct drm_device *dev, unsigned int type)
 309 {
 310         struct drm_minor *minor;
 311         unsigned long flags;
 312         int ret;
 313
 314         DRM_DEBUG("\n");
 315
 316         minor = *drm_minor_get_slot(dev, type);
 317         if (!minor)
 318                 return 0;
 319
 320         ret = drm_debugfs_init(minor, minor->index, drm_debugfs_root);
 321         if (ret) {
 322                 DRM_ERROR("DRM: Failed to initialize /sys/kernel/debug/dri.\n");
 323                 return ret;
 324         }
 325
 326         ret = device_add(minor->kdev);
 327         if (ret)
 328                 goto err_debugfs;
 329
 330         /* replace NULL with @minor so lookups will succeed from now on */
 331         spin_lock_irqsave(&drm_minor_lock, flags);
 332         idr_replace(&drm_minors_idr, minor, minor->index);
 333         spin_unlock_irqrestore(&drm_minor_lock, flags);
 334
 335         DRM_DEBUG("new minor registered %d\n", minor->index);
 336         return 0;
 337
 338 err_debugfs:
 339         drm_debugfs_cleanup(minor);
 340         return ret;
 341 }
 342
 343 static void drm_minor_unregister(struct drm_device *dev, unsigned int type)
 344 {
 345         struct drm_minor *minor;
 346         unsigned long flags;
 347
 348         minor = *drm_minor_get_slot(dev, type);
 349         if (!minor || !device_is_registered(minor->kdev))
 350                 return;
 351
 352         /* replace @minor with NULL so lookups will fail from now on */
 353         spin_lock_irqsave(&drm_minor_lock, flags);
 354         idr_replace(&drm_minors_idr, NULL, minor->index);
 355         spin_unlock_irqrestore(&drm_minor_lock, flags);
 356
 357         device_del(minor->kdev);
 358         dev_set_drvdata(minor->kdev, NULL); /* safety belt */
 359         drm_debugfs_cleanup(minor);
 360 }
 361
 362 /**
 363  * drm_minor_acquire - Acquire a DRM minor
 364  * @minor_id: Minor ID of the DRM-minor
 365  *
 366  * Looks up the given minor-ID and returns the respective DRM-minor object. The
 367  * refence-count of the underlying device is increased so you must release this
 368  * object with drm_minor_release().
 369  *
 370  * As long as you hold this minor, it is guaranteed that the object and the
 371  * minor->dev pointer will stay valid! However, the device may get unplugged and
 372  * unregistered while you hold the minor.
 373  *
 374  * Returns:
 375  * Pointer to minor-object with increased device-refcount, or PTR_ERR on
 376  * failure.
 377  */
 378 struct drm_minor *drm_minor_acquire(unsigned int minor_id)
 379 {
 380         struct drm_minor *minor;
 381         unsigned long flags;
 382
 383         spin_lock_irqsave(&drm_minor_lock, flags);
 384         minor = idr_find(&drm_minors_idr, minor_id);
 385         if (minor)
 386                 drm_dev_ref(minor->dev);
 387         spin_unlock_irqrestore(&drm_minor_lock, flags);
 388
 389         if (!minor) {
 390                 return ERR_PTR(-ENODEV);
 391         } else if (drm_device_is_unplugged(minor->dev)) {
 392                 drm_dev_unref(minor->dev);
 393                 return ERR_PTR(-ENODEV);
 394         }
 395
 396         return minor;
 397 }
 398
 399 /**
 400  * drm_minor_release - Release DRM minor
 401  * @minor: Pointer to DRM minor object
 402  *
 403  * Release a minor that was previously acquired via drm_minor_acquire().
 404  */
 405 void drm_minor_release(struct drm_minor *minor)
 406 {
 407         drm_dev_unref(minor->dev);
 408 }
 409
 410 /**
 411  * drm_put_dev - Unregister and release a DRM device
 412  * @dev: DRM device
 413  *
 414  * Called at module unload time or when a PCI device is unplugged.
 415  *
 416  * Use of this function is discouraged. It will eventually go away completely.
 417  * Please use drm_dev_unregister() and drm_dev_unref() explicitly instead.
 418  *
 419  * Cleans up all DRM device, calling drm_lastclose().
 420  */
 421 void drm_put_dev(struct drm_device *dev)
 422 {
 423         DRM_DEBUG("\n");
 424
 425         if (!dev) {
 426                 DRM_ERROR("cleanup called no dev\n");
 427                 return;
 428         }
 429
 430         drm_dev_unregister(dev);
 431         drm_dev_unref(dev);
 432 }
 433 EXPORT_SYMBOL(drm_put_dev);
 434
 435 void drm_unplug_dev(struct drm_device *dev)
 436 {
 437         /* for a USB device */
 438         drm_minor_unregister(dev, DRM_MINOR_LEGACY);
 439         drm_minor_unregister(dev, DRM_MINOR_RENDER);
 440         drm_minor_unregister(dev, DRM_MINOR_CONTROL);
 441
 442         mutex_lock(&drm_global_mutex);
 443
 444         drm_device_set_unplugged(dev);
 445
 446         if (dev->open_count == 0) {
 447                 drm_put_dev(dev);
 448         }
 449         mutex_unlock(&drm_global_mutex);
 450 }
 451 EXPORT_SYMBOL(drm_unplug_dev);
 452
 453 /*
 454  * DRM internal mount
 455  * We want to be able to allocate our own "struct address_space" to control
 456  * memory-mappings in VRAM (or stolen RAM, ...). However, core MM does not allow
 457  * stand-alone address_space objects, so we need an underlying inode. As there
 458  * is no way to allocate an independent inode easily, we need a fake internal
 459  * VFS mount-point.
 460  *
 461  * The drm_fs_inode_new() function allocates a new inode, drm_fs_inode_free()
 462  * frees it again. You are allowed to use iget() and iput() to get references to
 463  * the inode. But each drm_fs_inode_new() call must be paired with exactly one
 464  * drm_fs_inode_free() call (which does not have to be the last iput()).
 465  * We use drm_fs_inode_*() to manage our internal VFS mount-point and share it
 466  * between multiple inode-users. You could, technically, call
 467  * iget() + drm_fs_inode_free() directly after alloc and sometime later do an
 468  * iput(), but this way you'd end up with a new vfsmount for each inode.
 469  */
 470
 471 static int drm_fs_cnt;
 472 static struct vfsmount *drm_fs_mnt;
 473
 474 static const struct dentry_operations drm_fs_dops = {
 475         .d_dname        = simple_dname,
 476 };
 477
 478 static const struct super_operations drm_fs_sops = {
 479         .statfs         = simple_statfs,
 480 };
 481
 482 static struct dentry *drm_fs_mount(struct file_system_type *fs_type, int flags,
 483                                    const char *dev_name, void *data)
 484 {
 485         return mount_pseudo(fs_type,
 486                             "drm:",
 487                             &drm_fs_sops,
 488                             &drm_fs_dops,
 489                             0x010203ff);
 490 }
 491
 492 static struct file_system_type drm_fs_type = {
 493         .name           = "drm",
 494         .owner          = THIS_MODULE,
 495         .mount          = drm_fs_mount,
 496         .kill_sb        = kill_anon_super,
 497 };
 498
 499 static struct inode *drm_fs_inode_new(void)
 500 {
 501         struct inode *inode;
 502         int r;
 503
 504         r = simple_pin_fs(&drm_fs_type, &drm_fs_mnt, &drm_fs_cnt);
 505         if (r < 0) {
 506                 DRM_ERROR("Cannot mount pseudo fs: %d\n", r);
 507                 return ERR_PTR(r);
 508         }
 509
 510         inode = alloc_anon_inode(drm_fs_mnt->mnt_sb);
 511         if (IS_ERR(inode))
 512                 simple_release_fs(&drm_fs_mnt, &drm_fs_cnt);
 513
 514         return inode;
 515 }
 516
 517 static void drm_fs_inode_free(struct inode *inode)
 518 {
 519         if (inode) {
 520                 iput(inode);
 521                 simple_release_fs(&drm_fs_mnt, &drm_fs_cnt);
 522         }
 523 }
 524
 525 /**
 526  * drm_dev_alloc - Allocate new DRM device
 527  * @driver: DRM driver to allocate device for
 528  * @parent: Parent device object
 529  *
 530  * Allocate and initialize a new DRM device. No device registration is done.
 531  * Call drm_dev_register() to advertice the device to user space and register it
 532  * with other core subsystems.
 533  *
 534  * The initial ref-count of the object is 1. Use drm_dev_ref() and
 535  * drm_dev_unref() to take and drop further ref-counts.
 536  *
 537  * RETURNS:
 538  * Pointer to new DRM device, or NULL if out of memory.
 539  */
 540 struct drm_device *drm_dev_alloc(struct drm_driver *driver,
 541                                  struct device *parent)
 542 {
 543         struct drm_device *dev;
 544         int ret;
 545
 546         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 547         if (!dev)
 548                 return NULL;
 549
 550         kref_init(&dev->ref);
 551         dev->dev = parent;
 552         dev->driver = driver;
 553
 554         INIT_LIST_HEAD(&dev->filelist);
 555         INIT_LIST_HEAD(&dev->ctxlist);
 556         INIT_LIST_HEAD(&dev->vmalist);
 557         INIT_LIST_HEAD(&dev->maplist);
 558         INIT_LIST_HEAD(&dev->vblank_event_list);
 559
 560         spin_lock_init(&dev->buf_lock);
 561         spin_lock_init(&dev->event_lock);
 562         mutex_init(&dev->struct_mutex);
 563         mutex_init(&dev->ctxlist_mutex);
 564         mutex_init(&dev->master_mutex);
 565
 566         dev->anon_inode = drm_fs_inode_new();
 567         if (IS_ERR(dev->anon_inode)) {
 568                 ret = PTR_ERR(dev->anon_inode);
 569                 DRM_ERROR("Cannot allocate anonymous inode: %d\n", ret);
 570                 goto err_free;
 571         }
 572
 573         if (drm_core_check_feature(dev, DRIVER_MODESET)) {
 574                 ret = drm_minor_alloc(dev, DRM_MINOR_CONTROL);
 575                 if (ret)
 576                         goto err_minors;
 577         }
 578
 579         if (drm_core_check_feature(dev, DRIVER_RENDER)) {
 580                 ret = drm_minor_alloc(dev, DRM_MINOR_RENDER);
 581                 if (ret)
 582                         goto err_minors;
 583         }
 584
 585         ret = drm_minor_alloc(dev, DRM_MINOR_LEGACY);
 586         if (ret)
 587                 goto err_minors;
 588
 589         if (drm_ht_create(&dev->map_hash, 12))
 590                 goto err_minors;
 591
 592         ret = drm_legacy_ctxbitmap_init(dev);
 593         if (ret) {
 594                 DRM_ERROR("Cannot allocate memory for context bitmap.\n");
 595                 goto err_ht;
 596         }
 597
 598         if (drm_core_check_feature(dev, DRIVER_GEM)) {
 599                 ret = drm_gem_init(dev);
 600                 if (ret) {
 601                         DRM_ERROR("Cannot initialize graphics execution manager (GEM)\n");
 602                         goto err_ctxbitmap;
 603                 }
 604         }
 605
 606         return dev;
 607
 608 err_ctxbitmap:
 609         drm_legacy_ctxbitmap_cleanup(dev);
 610 err_ht:
 611         drm_ht_remove(&dev->map_hash);
 612 err_minors:
 613         drm_minor_free(dev, DRM_MINOR_LEGACY);
 614         drm_minor_free(dev, DRM_MINOR_RENDER);
 615         drm_minor_free(dev, DRM_MINOR_CONTROL);
 616         drm_fs_inode_free(dev->anon_inode);
 617 err_free:
 618         mutex_destroy(&dev->master_mutex);
 619         kfree(dev);
 620         return NULL;
 621 }
 622 EXPORT_SYMBOL(drm_dev_alloc);
 623
 624 static void drm_dev_release(struct kref *ref)
 625 {
 626         struct drm_device *dev = container_of(ref, struct drm_device, ref);
 627
 628         if (drm_core_check_feature(dev, DRIVER_GEM))
 629                 drm_gem_destroy(dev);
 630
 631         drm_legacy_ctxbitmap_cleanup(dev);
 632         drm_ht_remove(&dev->map_hash);
 633         drm_fs_inode_free(dev->anon_inode);
 634
 635         drm_minor_free(dev, DRM_MINOR_LEGACY);
 636         drm_minor_free(dev, DRM_MINOR_RENDER);
 637         drm_minor_free(dev, DRM_MINOR_CONTROL);
 638
 639         mutex_destroy(&dev->master_mutex);
 640         kfree(dev->unique);
 641         kfree(dev);
 642 }
 643
 644 /**
 645  * drm_dev_ref - Take reference of a DRM device
 646  * @dev: device to take reference of or NULL
 647  *
 648  * This increases the ref-count of @dev by one. You *must* already own a
 649  * reference when calling this. Use drm_dev_unref() to drop this reference
 650  * again.
 651  *
 652  * This function never fails. However, this function does not provide *any*
 653  * guarantee whether the device is alive or running. It only provides a
 654  * reference to the object and the memory associated with it.
 655  */
 656 void drm_dev_ref(struct drm_device *dev)
 657 {
 658         if (dev)
 659                 kref_get(&dev->ref);
 660 }
 661 EXPORT_SYMBOL(drm_dev_ref);
 662
 663 /**
 664  * drm_dev_unref - Drop reference of a DRM device
 665  * @dev: device to drop reference of or NULL
 666  *
 667  * This decreases the ref-count of @dev by one. The device is destroyed if the
 668  * ref-count drops to zero.
 669  */
 670 void drm_dev_unref(struct drm_device *dev)
 671 {
 672         if (dev)
 673                 kref_put(&dev->ref, drm_dev_release);
 674 }
 675 EXPORT_SYMBOL(drm_dev_unref);
 676
 677 /**
 678  * drm_dev_register - Register DRM device
 679  * @dev: Device to register
 680  * @flags: Flags passed to the driver's .load() function
 681  *
 682  * Register the DRM device @dev with the system, advertise device to user-space
 683  * and start normal device operation. @dev must be allocated via drm_dev_alloc()
 684  * previously.
 685  *
 686  * Never call this twice on any device!
 687  *
 688  * RETURNS:
 689  * 0 on success, negative error code on failure.
 690  */
 691 int drm_dev_register(struct drm_device *dev, unsigned long flags)
 692 {
 693         int ret;
 694
 695         mutex_lock(&drm_global_mutex);
 696
 697         ret = drm_minor_register(dev, DRM_MINOR_CONTROL);
 698         if (ret)
 699                 goto err_minors;
 700
 701         ret = drm_minor_register(dev, DRM_MINOR_RENDER);
 702         if (ret)
 703                 goto err_minors;
 704
 705         ret = drm_minor_register(dev, DRM_MINOR_LEGACY);
 706         if (ret)
 707                 goto err_minors;
 708
 709         if (dev->driver->load) {
 710                 ret = dev->driver->load(dev, flags);
 711                 if (ret)
 712                         goto err_minors;
 713         }
 714
 715         /* setup grouping for legacy outputs */
 716         if (drm_core_check_feature(dev, DRIVER_MODESET)) {
 717                 ret = drm_mode_group_init_legacy_group(dev,
 718                                 &dev->primary->mode_group);
 719                 if (ret)
 720                         goto err_unload;
 721         }
 722
 723         ret = 0;
 724         goto out_unlock;
 725
 726 err_unload:
 727         if (dev->driver->unload)
 728                 dev->driver->unload(dev);
 729 err_minors:
 730         drm_minor_unregister(dev, DRM_MINOR_LEGACY);
 731         drm_minor_unregister(dev, DRM_MINOR_RENDER);
 732         drm_minor_unregister(dev, DRM_MINOR_CONTROL);
 733 out_unlock:
 734         mutex_unlock(&drm_global_mutex);
 735         return ret;
 736 }
 737 EXPORT_SYMBOL(drm_dev_register);
 738
 739 /**
 740  * drm_dev_unregister - Unregister DRM device
 741  * @dev: Device to unregister
 742  *
 743  * Unregister the DRM device from the system. This does the reverse of
 744  * drm_dev_register() but does not deallocate the device. The caller must call
 745  * drm_dev_unref() to drop their final reference.
 746  */
 747 void drm_dev_unregister(struct drm_device *dev)
 748 {
 749         struct drm_map_list *r_list, *list_temp;
 750
 751         drm_lastclose(dev);
 752
 753         if (dev->driver->unload)
 754                 dev->driver->unload(dev);
 755
 756         if (dev->agp)
 757                 drm_pci_agp_destroy(dev);
 758
 759         drm_vblank_cleanup(dev);
 760
 761         list_for_each_entry_safe(r_list, list_temp, &dev->maplist, head)
 762                 drm_legacy_rmmap(dev, r_list->map);
 763
 764         drm_minor_unregister(dev, DRM_MINOR_LEGACY);
 765         drm_minor_unregister(dev, DRM_MINOR_RENDER);
 766         drm_minor_unregister(dev, DRM_MINOR_CONTROL);
 767 }
 768 EXPORT_SYMBOL(drm_dev_unregister);
 769
 770 /**
 771  * drm_dev_set_unique - Set the unique name of a DRM device
 772  * @dev: device of which to set the unique name
 773  * @fmt: format string for unique name
 774  *
 775  * Sets the unique name of a DRM device using the specified format string and
 776  * a variable list of arguments. Drivers can use this at driver probe time if
 777  * the unique name of the devices they drive is static.
 778  *
 779  * Return: 0 on success or a negative error code on failure.
 780  */
 781 int drm_dev_set_unique(struct drm_device *dev, const char *fmt, ...)
 782 {
 783         va_list ap;
 784
 785         kfree(dev->unique);
 786
 787         va_start(ap, fmt);
 788         dev->unique = kvasprintf(GFP_KERNEL, fmt, ap);
 789         va_end(ap);
 790
 791         return dev->unique ? 0 : -ENOMEM;
 792 }
 793 EXPORT_SYMBOL(drm_dev_set_unique);
 794
 795 /*
 796  * DRM Core
 797  * The DRM core module initializes all global DRM objects and makes them
 798  * available to drivers. Once setup, drivers can probe their respective
 799  * devices.
 800  * Currently, core management includes:
 801  *  - The "DRM-Global" key/value database
 802  *  - Global ID management for connectors
 803  *  - DRM major number allocation
 804  *  - DRM minor management
 805  *  - DRM sysfs class
 806  *  - DRM debugfs root
 807  *
 808  * Furthermore, the DRM core provides dynamic char-dev lookups. For each
 809  * interface registered on a DRM device, you can request minor numbers from DRM
 810  * core. DRM core takes care of major-number management and char-dev
 811  * registration. A stub ->open() callback forwards any open() requests to the
 812  * registered minor.
 813  */
 814
 815 static int drm_stub_open(struct inode *inode, struct file *filp)
 816 {
 817         const struct file_operations *new_fops;
 818         struct drm_minor *minor;
 819         int err;
 820
 821         DRM_DEBUG("\n");
 822
 823         mutex_lock(&drm_global_mutex);
 824         minor = drm_minor_acquire(iminor(inode));
 825         if (IS_ERR(minor)) {
 826                 err = PTR_ERR(minor);
 827                 goto out_unlock;
 828         }
 829
 830         new_fops = fops_get(minor->dev->driver->fops);
 831         if (!new_fops) {
 832                 err = -ENODEV;
 833                 goto out_release;
 834         }
 835
 836         replace_fops(filp, new_fops);
 837         if (filp->f_op->open)
 838                 err = filp->f_op->open(inode, filp);
 839         else
 840                 err = 0;
 841
 842 out_release:
 843         drm_minor_release(minor);
 844 out_unlock:
 845         mutex_unlock(&drm_global_mutex);
 846         return err;
 847 }
 848
 849 static const struct file_operations drm_stub_fops = {
 850         .owner = THIS_MODULE,
 851         .open = drm_stub_open,
 852         .llseek = noop_llseek,
 853 };
 854
 855 static int __init drm_core_init(void)
 856 {
 857         int ret = -ENOMEM;
 858
 859         drm_global_init();
 860         drm_connector_ida_init();
 861         idr_init(&drm_minors_idr);
 862
 863         if (register_chrdev(DRM_MAJOR, "drm", &drm_stub_fops))
 864                 goto err_p1;
 865
 866         drm_class = drm_sysfs_create(THIS_MODULE, "drm");
 867         if (IS_ERR(drm_class)) {
 868                 printk(KERN_ERR "DRM: Error creating drm class.\n");
 869                 ret = PTR_ERR(drm_class);
 870                 goto err_p2;
 871         }
 872
 873         drm_debugfs_root = debugfs_create_dir("dri", NULL);
 874         if (!drm_debugfs_root) {
 875                 DRM_ERROR("Cannot create /sys/kernel/debug/dri\n");
 876                 ret = -1;
 877                 goto err_p3;
 878         }
 879
 880         DRM_INFO("Initialized %s %d.%d.%d %s\n",
 881                  CORE_NAME, CORE_MAJOR, CORE_MINOR, CORE_PATCHLEVEL, CORE_DATE);
 882         return 0;
 883 err_p3:
 884         drm_sysfs_destroy();
 885 err_p2:
 886         unregister_chrdev(DRM_MAJOR, "drm");
 887
 888         idr_destroy(&drm_minors_idr);
 889 err_p1:
 890         return ret;
 891 }
 892
 893 static void __exit drm_core_exit(void)
 894 {
 895         debugfs_remove(drm_debugfs_root);
 896         drm_sysfs_destroy();
 897
 898         unregister_chrdev(DRM_MAJOR, "drm");
 899
 900         drm_connector_ida_destroy();
 901         idr_destroy(&drm_minors_idr);
 902 }
 903
 904 module_init(drm_core_init);
 905 module_exit(drm_core_exit);