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 bool drm_atomic = 0;
  44
  45 MODULE_AUTHOR(CORE_AUTHOR);
  46 MODULE_DESCRIPTION(CORE_DESC);
  47 MODULE_LICENSE("GPL and additional rights");
  48 MODULE_PARM_DESC(debug, "Enable debug output");
  49 MODULE_PARM_DESC(atomic, "Enable experimental atomic KMS API");
  50 MODULE_PARM_DESC(vblankoffdelay, "Delay until vblank irq auto-disable [msecs] (0: never disable, <0: disable immediately)");
  51 MODULE_PARM_DESC(timestamp_precision_usec, "Max. error on timestamps [usecs]");
  52 MODULE_PARM_DESC(timestamp_monotonic, "Use monotonic timestamps");
  53
  54 module_param_named(debug, drm_debug, int, 0600);
  55 module_param_named_unsafe(atomic, drm_atomic, bool, 0600);
  56
  57 static DEFINE_SPINLOCK(drm_minor_lock);
  58 static struct idr drm_minors_idr;
  59
  60 struct class *drm_class;
  61 static struct dentry *drm_debugfs_root;
  62
  63 void drm_err(const char *format, ...)
  64 {
  65         struct va_format vaf;
  66         va_list args;
  67
  68         va_start(args, format);
  69
  70         vaf.fmt = format;
  71         vaf.va = &args;
  72
  73         printk(KERN_ERR "[" DRM_NAME ":%ps] *ERROR* %pV",
  74                __builtin_return_address(0), &vaf);
  75
  76         va_end(args);
  77 }
  78 EXPORT_SYMBOL(drm_err);
  79
  80 void drm_ut_debug_printk(const char *function_name, const char *format, ...)
  81 {
  82         struct va_format vaf;
  83         va_list args;
  84
  85         va_start(args, format);
  86         vaf.fmt = format;
  87         vaf.va = &args;
  88
  89         printk(KERN_DEBUG "[" DRM_NAME ":%s] %pV", function_name, &vaf);
  90
  91         va_end(args);
  92 }
  93 EXPORT_SYMBOL(drm_ut_debug_printk);
  94
  95 struct drm_master *drm_master_create(struct drm_minor *minor)
  96 {
  97         struct drm_master *master;
  98
  99         master = kzalloc(sizeof(*master), GFP_KERNEL);
 100         if (!master)
 101                 return NULL;
 102
 103         kref_init(&master->refcount);
 104         spin_lock_init(&master->lock.spinlock);
 105         init_waitqueue_head(&master->lock.lock_queue);
 106         idr_init(&master->magic_map);
 107         master->minor = minor;
 108
 109         return master;
 110 }
 111
 112 struct drm_master *drm_master_get(struct drm_master *master)
 113 {
 114         kref_get(&master->refcount);
 115         return master;
 116 }
 117 EXPORT_SYMBOL(drm_master_get);
 118
 119 static void drm_master_destroy(struct kref *kref)
 120 {
 121         struct drm_master *master = container_of(kref, struct drm_master, refcount);
 122         struct drm_device *dev = master->minor->dev;
 123         struct drm_map_list *r_list, *list_temp;
 124
 125         mutex_lock(&dev->struct_mutex);
 126         if (dev->driver->master_destroy)
 127                 dev->driver->master_destroy(dev, master);
 128
 129         list_for_each_entry_safe(r_list, list_temp, &dev->maplist, head) {
 130                 if (r_list->master == master) {
 131                         drm_legacy_rmmap_locked(dev, r_list->map);
 132                         r_list = NULL;
 133                 }
 134         }
 135         mutex_unlock(&dev->struct_mutex);
 136
 137         idr_destroy(&master->magic_map);
 138         kfree(master->unique);
 139         kfree(master);
 140 }
 141
 142 void drm_master_put(struct drm_master **master)
 143 {
 144         kref_put(&(*master)->refcount, drm_master_destroy);
 145         *master = NULL;
 146 }
 147 EXPORT_SYMBOL(drm_master_put);
 148
 149 int drm_setmaster_ioctl(struct drm_device *dev, void *data,
 150                         struct drm_file *file_priv)
 151 {
 152         int ret = 0;
 153
 154         mutex_lock(&dev->master_mutex);
 155         if (file_priv->is_master)
 156                 goto out_unlock;
 157
 158         if (file_priv->minor->master) {
 159                 ret = -EINVAL;
 160                 goto out_unlock;
 161         }
 162
 163         if (!file_priv->master) {
 164                 ret = -EINVAL;
 165                 goto out_unlock;
 166         }
 167
 168         file_priv->minor->master = drm_master_get(file_priv->master);
 169         file_priv->is_master = 1;
 170         if (dev->driver->master_set) {
 171                 ret = dev->driver->master_set(dev, file_priv, false);
 172                 if (unlikely(ret != 0)) {
 173                         file_priv->is_master = 0;
 174                         drm_master_put(&file_priv->minor->master);
 175                 }
 176         }
 177
 178 out_unlock:
 179         mutex_unlock(&dev->master_mutex);
 180         return ret;
 181 }
 182
 183 int drm_dropmaster_ioctl(struct drm_device *dev, void *data,
 184                          struct drm_file *file_priv)
 185 {
 186         int ret = -EINVAL;
 187
 188         mutex_lock(&dev->master_mutex);
 189         if (!file_priv->is_master)
 190                 goto out_unlock;
 191
 192         if (!file_priv->minor->master)
 193                 goto out_unlock;
 194
 195         ret = 0;
 196         if (dev->driver->master_drop)
 197                 dev->driver->master_drop(dev, file_priv, false);
 198         drm_master_put(&file_priv->minor->master);
 199         file_priv->is_master = 0;
 200
 201 out_unlock:
 202         mutex_unlock(&dev->master_mutex);
 203         return ret;
 204 }
 205
 206 /*
 207  * DRM Minors
 208  * A DRM device can provide several char-dev interfaces on the DRM-Major. Each
 209  * of them is represented by a drm_minor object. Depending on the capabilities
 210  * of the device-driver, different interfaces are registered.
 211  *
 212  * Minors can be accessed via dev->$minor_name. This pointer is either
 213  * NULL or a valid drm_minor pointer and stays valid as long as the device is
 214  * valid. This means, DRM minors have the same life-time as the underlying
 215  * device. However, this doesn't mean that the minor is active. Minors are
 216  * registered and unregistered dynamically according to device-state.
 217  */
 218
 219 static struct drm_minor **drm_minor_get_slot(struct drm_device *dev,
 220                                              unsigned int type)
 221 {
 222         switch (type) {
 223         case DRM_MINOR_LEGACY:
 224                 return &dev->primary;
 225         case DRM_MINOR_RENDER:
 226                 return &dev->render;
 227         case DRM_MINOR_CONTROL:
 228                 return &dev->control;
 229         default:
 230                 return NULL;
 231         }
 232 }
 233
 234 static int drm_minor_alloc(struct drm_device *dev, unsigned int type)
 235 {
 236         struct drm_minor *minor;
 237         unsigned long flags;
 238         int r;
 239
 240         minor = kzalloc(sizeof(*minor), GFP_KERNEL);
 241         if (!minor)
 242                 return -ENOMEM;
 243
 244         minor->type = type;
 245         minor->dev = dev;
 246
 247         idr_preload(GFP_KERNEL);
 248         spin_lock_irqsave(&drm_minor_lock, flags);
 249         r = idr_alloc(&drm_minors_idr,
 250                       NULL,
 251                       64 * type,
 252                       64 * (type + 1),
 253                       GFP_NOWAIT);
 254         spin_unlock_irqrestore(&drm_minor_lock, flags);
 255         idr_preload_end();
 256
 257         if (r < 0)
 258                 goto err_free;
 259
 260         minor->index = r;
 261
 262         minor->kdev = drm_sysfs_minor_alloc(minor);
 263         if (IS_ERR(minor->kdev)) {
 264                 r = PTR_ERR(minor->kdev);
 265                 goto err_index;
 266         }
 267
 268         *drm_minor_get_slot(dev, type) = minor;
 269         return 0;
 270
 271 err_index:
 272         spin_lock_irqsave(&drm_minor_lock, flags);
 273         idr_remove(&drm_minors_idr, minor->index);
 274         spin_unlock_irqrestore(&drm_minor_lock, flags);
 275 err_free:
 276         kfree(minor);
 277         return r;
 278 }
 279
 280 static void drm_minor_free(struct drm_device *dev, unsigned int type)
 281 {
 282         struct drm_minor **slot, *minor;
 283         unsigned long flags;
 284
 285         slot = drm_minor_get_slot(dev, type);
 286         minor = *slot;
 287         if (!minor)
 288                 return;
 289
 290         drm_mode_group_destroy(&minor->mode_group);
 291         put_device(minor->kdev);
 292
 293         spin_lock_irqsave(&drm_minor_lock, flags);
 294         idr_remove(&drm_minors_idr, minor->index);
 295         spin_unlock_irqrestore(&drm_minor_lock, flags);
 296
 297         kfree(minor);
 298         *slot = NULL;
 299 }
 300
 301 static int drm_minor_register(struct drm_device *dev, unsigned int type)
 302 {
 303         struct drm_minor *minor;
 304         unsigned long flags;
 305         int ret;
 306
 307         DRM_DEBUG("\n");
 308
 309         minor = *drm_minor_get_slot(dev, type);
 310         if (!minor)
 311                 return 0;
 312
 313         ret = drm_debugfs_init(minor, minor->index, drm_debugfs_root);
 314         if (ret) {
 315                 DRM_ERROR("DRM: Failed to initialize /sys/kernel/debug/dri.\n");
 316                 return ret;
 317         }
 318
 319         ret = device_add(minor->kdev);
 320         if (ret)
 321                 goto err_debugfs;
 322
 323         /* replace NULL with @minor so lookups will succeed from now on */
 324         spin_lock_irqsave(&drm_minor_lock, flags);
 325         idr_replace(&drm_minors_idr, minor, minor->index);
 326         spin_unlock_irqrestore(&drm_minor_lock, flags);
 327
 328         DRM_DEBUG("new minor registered %d\n", minor->index);
 329         return 0;
 330
 331 err_debugfs:
 332         drm_debugfs_cleanup(minor);
 333         return ret;
 334 }
 335
 336 static void drm_minor_unregister(struct drm_device *dev, unsigned int type)
 337 {
 338         struct drm_minor *minor;
 339         unsigned long flags;
 340
 341         minor = *drm_minor_get_slot(dev, type);
 342         if (!minor || !device_is_registered(minor->kdev))
 343                 return;
 344
 345         /* replace @minor with NULL so lookups will fail from now on */
 346         spin_lock_irqsave(&drm_minor_lock, flags);
 347         idr_replace(&drm_minors_idr, NULL, minor->index);
 348         spin_unlock_irqrestore(&drm_minor_lock, flags);
 349
 350         device_del(minor->kdev);
 351         dev_set_drvdata(minor->kdev, NULL); /* safety belt */
 352         drm_debugfs_cleanup(minor);
 353 }
 354
 355 /**
 356  * drm_minor_acquire - Acquire a DRM minor
 357  * @minor_id: Minor ID of the DRM-minor
 358  *
 359  * Looks up the given minor-ID and returns the respective DRM-minor object. The
 360  * refence-count of the underlying device is increased so you must release this
 361  * object with drm_minor_release().
 362  *
 363  * As long as you hold this minor, it is guaranteed that the object and the
 364  * minor->dev pointer will stay valid! However, the device may get unplugged and
 365  * unregistered while you hold the minor.
 366  *
 367  * Returns:
 368  * Pointer to minor-object with increased device-refcount, or PTR_ERR on
 369  * failure.
 370  */
 371 struct drm_minor *drm_minor_acquire(unsigned int minor_id)
 372 {
 373         struct drm_minor *minor;
 374         unsigned long flags;
 375
 376         spin_lock_irqsave(&drm_minor_lock, flags);
 377         minor = idr_find(&drm_minors_idr, minor_id);
 378         if (minor)
 379                 drm_dev_ref(minor->dev);
 380         spin_unlock_irqrestore(&drm_minor_lock, flags);
 381
 382         if (!minor) {
 383                 return ERR_PTR(-ENODEV);
 384         } else if (drm_device_is_unplugged(minor->dev)) {
 385                 drm_dev_unref(minor->dev);
 386                 return ERR_PTR(-ENODEV);
 387         }
 388
 389         return minor;
 390 }
 391
 392 /**
 393  * drm_minor_release - Release DRM minor
 394  * @minor: Pointer to DRM minor object
 395  *
 396  * Release a minor that was previously acquired via drm_minor_acquire().
 397  */
 398 void drm_minor_release(struct drm_minor *minor)
 399 {
 400         drm_dev_unref(minor->dev);
 401 }
 402
 403 /**
 404  * drm_put_dev - Unregister and release a DRM device
 405  * @dev: DRM device
 406  *
 407  * Called at module unload time or when a PCI device is unplugged.
 408  *
 409  * Use of this function is discouraged. It will eventually go away completely.
 410  * Please use drm_dev_unregister() and drm_dev_unref() explicitly instead.
 411  *
 412  * Cleans up all DRM device, calling drm_lastclose().
 413  */
 414 void drm_put_dev(struct drm_device *dev)
 415 {
 416         DRM_DEBUG("\n");
 417
 418         if (!dev) {
 419                 DRM_ERROR("cleanup called no dev\n");
 420                 return;
 421         }
 422
 423         drm_dev_unregister(dev);
 424         drm_dev_unref(dev);
 425 }
 426 EXPORT_SYMBOL(drm_put_dev);
 427
 428 void drm_unplug_dev(struct drm_device *dev)
 429 {
 430         /* for a USB device */
 431         drm_minor_unregister(dev, DRM_MINOR_LEGACY);
 432         drm_minor_unregister(dev, DRM_MINOR_RENDER);
 433         drm_minor_unregister(dev, DRM_MINOR_CONTROL);
 434
 435         mutex_lock(&drm_global_mutex);
 436
 437         drm_device_set_unplugged(dev);
 438
 439         if (dev->open_count == 0) {
 440                 drm_put_dev(dev);
 441         }
 442         mutex_unlock(&drm_global_mutex);
 443 }
 444 EXPORT_SYMBOL(drm_unplug_dev);
 445
 446 /*
 447  * DRM internal mount
 448  * We want to be able to allocate our own "struct address_space" to control
 449  * memory-mappings in VRAM (or stolen RAM, ...). However, core MM does not allow
 450  * stand-alone address_space objects, so we need an underlying inode. As there
 451  * is no way to allocate an independent inode easily, we need a fake internal
 452  * VFS mount-point.
 453  *
 454  * The drm_fs_inode_new() function allocates a new inode, drm_fs_inode_free()
 455  * frees it again. You are allowed to use iget() and iput() to get references to
 456  * the inode. But each drm_fs_inode_new() call must be paired with exactly one
 457  * drm_fs_inode_free() call (which does not have to be the last iput()).
 458  * We use drm_fs_inode_*() to manage our internal VFS mount-point and share it
 459  * between multiple inode-users. You could, technically, call
 460  * iget() + drm_fs_inode_free() directly after alloc and sometime later do an
 461  * iput(), but this way you'd end up with a new vfsmount for each inode.
 462  */
 463
 464 static int drm_fs_cnt;
 465 static struct vfsmount *drm_fs_mnt;
 466
 467 static const struct dentry_operations drm_fs_dops = {
 468         .d_dname        = simple_dname,
 469 };
 470
 471 static const struct super_operations drm_fs_sops = {
 472         .statfs         = simple_statfs,
 473 };
 474
 475 static struct dentry *drm_fs_mount(struct file_system_type *fs_type, int flags,
 476                                    const char *dev_name, void *data)
 477 {
 478         return mount_pseudo(fs_type,
 479                             "drm:",
 480                             &drm_fs_sops,
 481                             &drm_fs_dops,
 482                             0x010203ff);
 483 }
 484
 485 static struct file_system_type drm_fs_type = {
 486         .name           = "drm",
 487         .owner          = THIS_MODULE,
 488         .mount          = drm_fs_mount,
 489         .kill_sb        = kill_anon_super,
 490 };
 491
 492 static struct inode *drm_fs_inode_new(void)
 493 {
 494         struct inode *inode;
 495         int r;
 496
 497         r = simple_pin_fs(&drm_fs_type, &drm_fs_mnt, &drm_fs_cnt);
 498         if (r < 0) {
 499                 DRM_ERROR("Cannot mount pseudo fs: %d\n", r);
 500                 return ERR_PTR(r);
 501         }
 502
 503         inode = alloc_anon_inode(drm_fs_mnt->mnt_sb);
 504         if (IS_ERR(inode))
 505                 simple_release_fs(&drm_fs_mnt, &drm_fs_cnt);
 506
 507         return inode;
 508 }
 509
 510 static void drm_fs_inode_free(struct inode *inode)
 511 {
 512         if (inode) {
 513                 iput(inode);
 514                 simple_release_fs(&drm_fs_mnt, &drm_fs_cnt);
 515         }
 516 }
 517
 518 /**
 519  * drm_dev_alloc - Allocate new DRM device
 520  * @driver: DRM driver to allocate device for
 521  * @parent: Parent device object
 522  *
 523  * Allocate and initialize a new DRM device. No device registration is done.
 524  * Call drm_dev_register() to advertice the device to user space and register it
 525  * with other core subsystems.
 526  *
 527  * The initial ref-count of the object is 1. Use drm_dev_ref() and
 528  * drm_dev_unref() to take and drop further ref-counts.
 529  *
 530  * Note that for purely virtual devices @parent can be NULL.
 531  *
 532  * RETURNS:
 533  * Pointer to new DRM device, or NULL if out of memory.
 534  */
 535 struct drm_device *drm_dev_alloc(struct drm_driver *driver,
 536                                  struct device *parent)
 537 {
 538         struct drm_device *dev;
 539         int ret;
 540
 541         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 542         if (!dev)
 543                 return NULL;
 544
 545         kref_init(&dev->ref);
 546         dev->dev = parent;
 547         dev->driver = driver;
 548
 549         INIT_LIST_HEAD(&dev->filelist);
 550         INIT_LIST_HEAD(&dev->ctxlist);
 551         INIT_LIST_HEAD(&dev->vmalist);
 552         INIT_LIST_HEAD(&dev->maplist);
 553         INIT_LIST_HEAD(&dev->vblank_event_list);
 554
 555         spin_lock_init(&dev->buf_lock);
 556         spin_lock_init(&dev->event_lock);
 557         mutex_init(&dev->struct_mutex);
 558         mutex_init(&dev->ctxlist_mutex);
 559         mutex_init(&dev->master_mutex);
 560
 561         dev->anon_inode = drm_fs_inode_new();
 562         if (IS_ERR(dev->anon_inode)) {
 563                 ret = PTR_ERR(dev->anon_inode);
 564                 DRM_ERROR("Cannot allocate anonymous inode: %d\n", ret);
 565                 goto err_free;
 566         }
 567
 568         if (drm_core_check_feature(dev, DRIVER_MODESET)) {
 569                 ret = drm_minor_alloc(dev, DRM_MINOR_CONTROL);
 570                 if (ret)
 571                         goto err_minors;
 572         }
 573
 574         if (drm_core_check_feature(dev, DRIVER_RENDER)) {
 575                 ret = drm_minor_alloc(dev, DRM_MINOR_RENDER);
 576                 if (ret)
 577                         goto err_minors;
 578         }
 579
 580         ret = drm_minor_alloc(dev, DRM_MINOR_LEGACY);
 581         if (ret)
 582                 goto err_minors;
 583
 584         if (drm_ht_create(&dev->map_hash, 12))
 585                 goto err_minors;
 586
 587         ret = drm_legacy_ctxbitmap_init(dev);
 588         if (ret) {
 589                 DRM_ERROR("Cannot allocate memory for context bitmap.\n");
 590                 goto err_ht;
 591         }
 592
 593         if (drm_core_check_feature(dev, DRIVER_GEM)) {
 594                 ret = drm_gem_init(dev);
 595                 if (ret) {
 596                         DRM_ERROR("Cannot initialize graphics execution manager (GEM)\n");
 597                         goto err_ctxbitmap;
 598                 }
 599         }
 600
 601         return dev;
 602
 603 err_ctxbitmap:
 604         drm_legacy_ctxbitmap_cleanup(dev);
 605 err_ht:
 606         drm_ht_remove(&dev->map_hash);
 607 err_minors:
 608         drm_minor_free(dev, DRM_MINOR_LEGACY);
 609         drm_minor_free(dev, DRM_MINOR_RENDER);
 610         drm_minor_free(dev, DRM_MINOR_CONTROL);
 611         drm_fs_inode_free(dev->anon_inode);
 612 err_free:
 613         mutex_destroy(&dev->master_mutex);
 614         kfree(dev);
 615         return NULL;
 616 }
 617 EXPORT_SYMBOL(drm_dev_alloc);
 618
 619 static void drm_dev_release(struct kref *ref)
 620 {
 621         struct drm_device *dev = container_of(ref, struct drm_device, ref);
 622
 623         if (drm_core_check_feature(dev, DRIVER_GEM))
 624                 drm_gem_destroy(dev);
 625
 626         drm_legacy_ctxbitmap_cleanup(dev);
 627         drm_ht_remove(&dev->map_hash);
 628         drm_fs_inode_free(dev->anon_inode);
 629
 630         drm_minor_free(dev, DRM_MINOR_LEGACY);
 631         drm_minor_free(dev, DRM_MINOR_RENDER);
 632         drm_minor_free(dev, DRM_MINOR_CONTROL);
 633
 634         mutex_destroy(&dev->master_mutex);
 635         kfree(dev->unique);
 636         kfree(dev);
 637 }
 638
 639 /**
 640  * drm_dev_ref - Take reference of a DRM device
 641  * @dev: device to take reference of or NULL
 642  *
 643  * This increases the ref-count of @dev by one. You *must* already own a
 644  * reference when calling this. Use drm_dev_unref() to drop this reference
 645  * again.
 646  *
 647  * This function never fails. However, this function does not provide *any*
 648  * guarantee whether the device is alive or running. It only provides a
 649  * reference to the object and the memory associated with it.
 650  */
 651 void drm_dev_ref(struct drm_device *dev)
 652 {
 653         if (dev)
 654                 kref_get(&dev->ref);
 655 }
 656 EXPORT_SYMBOL(drm_dev_ref);
 657
 658 /**
 659  * drm_dev_unref - Drop reference of a DRM device
 660  * @dev: device to drop reference of or NULL
 661  *
 662  * This decreases the ref-count of @dev by one. The device is destroyed if the
 663  * ref-count drops to zero.
 664  */
 665 void drm_dev_unref(struct drm_device *dev)
 666 {
 667         if (dev)
 668                 kref_put(&dev->ref, drm_dev_release);
 669 }
 670 EXPORT_SYMBOL(drm_dev_unref);
 671
 672 /**
 673  * drm_dev_register - Register DRM device
 674  * @dev: Device to register
 675  * @flags: Flags passed to the driver's .load() function
 676  *
 677  * Register the DRM device @dev with the system, advertise device to user-space
 678  * and start normal device operation. @dev must be allocated via drm_dev_alloc()
 679  * previously.
 680  *
 681  * Never call this twice on any device!
 682  *
 683  * RETURNS:
 684  * 0 on success, negative error code on failure.
 685  */
 686 int drm_dev_register(struct drm_device *dev, unsigned long flags)
 687 {
 688         int ret;
 689
 690         mutex_lock(&drm_global_mutex);
 691
 692         ret = drm_minor_register(dev, DRM_MINOR_CONTROL);
 693         if (ret)
 694                 goto err_minors;
 695
 696         ret = drm_minor_register(dev, DRM_MINOR_RENDER);
 697         if (ret)
 698                 goto err_minors;
 699
 700         ret = drm_minor_register(dev, DRM_MINOR_LEGACY);
 701         if (ret)
 702                 goto err_minors;
 703
 704         if (dev->driver->load) {
 705                 ret = dev->driver->load(dev, flags);
 706                 if (ret)
 707                         goto err_minors;
 708         }
 709
 710         /* setup grouping for legacy outputs */
 711         if (drm_core_check_feature(dev, DRIVER_MODESET)) {
 712                 ret = drm_mode_group_init_legacy_group(dev,
 713                                 &dev->primary->mode_group);
 714                 if (ret)
 715                         goto err_unload;
 716         }
 717
 718         ret = 0;
 719         goto out_unlock;
 720
 721 err_unload:
 722         if (dev->driver->unload)
 723                 dev->driver->unload(dev);
 724 err_minors:
 725         drm_minor_unregister(dev, DRM_MINOR_LEGACY);
 726         drm_minor_unregister(dev, DRM_MINOR_RENDER);
 727         drm_minor_unregister(dev, DRM_MINOR_CONTROL);
 728 out_unlock:
 729         mutex_unlock(&drm_global_mutex);
 730         return ret;
 731 }
 732 EXPORT_SYMBOL(drm_dev_register);
 733
 734 /**
 735  * drm_dev_unregister - Unregister DRM device
 736  * @dev: Device to unregister
 737  *
 738  * Unregister the DRM device from the system. This does the reverse of
 739  * drm_dev_register() but does not deallocate the device. The caller must call
 740  * drm_dev_unref() to drop their final reference.
 741  */
 742 void drm_dev_unregister(struct drm_device *dev)
 743 {
 744         struct drm_map_list *r_list, *list_temp;
 745
 746         drm_lastclose(dev);
 747
 748         if (dev->driver->unload)
 749                 dev->driver->unload(dev);
 750
 751         if (dev->agp)
 752                 drm_pci_agp_destroy(dev);
 753
 754         drm_vblank_cleanup(dev);
 755
 756         list_for_each_entry_safe(r_list, list_temp, &dev->maplist, head)
 757                 drm_legacy_rmmap(dev, r_list->map);
 758
 759         drm_minor_unregister(dev, DRM_MINOR_LEGACY);
 760         drm_minor_unregister(dev, DRM_MINOR_RENDER);
 761         drm_minor_unregister(dev, DRM_MINOR_CONTROL);
 762 }
 763 EXPORT_SYMBOL(drm_dev_unregister);
 764
 765 /**
 766  * drm_dev_set_unique - Set the unique name of a DRM device
 767  * @dev: device of which to set the unique name
 768  * @fmt: format string for unique name
 769  *
 770  * Sets the unique name of a DRM device using the specified format string and
 771  * a variable list of arguments. Drivers can use this at driver probe time if
 772  * the unique name of the devices they drive is static.
 773  *
 774  * Return: 0 on success or a negative error code on failure.
 775  */
 776 int drm_dev_set_unique(struct drm_device *dev, const char *fmt, ...)
 777 {
 778         va_list ap;
 779
 780         kfree(dev->unique);
 781
 782         va_start(ap, fmt);
 783         dev->unique = kvasprintf(GFP_KERNEL, fmt, ap);
 784         va_end(ap);
 785
 786         return dev->unique ? 0 : -ENOMEM;
 787 }
 788 EXPORT_SYMBOL(drm_dev_set_unique);
 789
 790 /*
 791  * DRM Core
 792  * The DRM core module initializes all global DRM objects and makes them
 793  * available to drivers. Once setup, drivers can probe their respective
 794  * devices.
 795  * Currently, core management includes:
 796  *  - The "DRM-Global" key/value database
 797  *  - Global ID management for connectors
 798  *  - DRM major number allocation
 799  *  - DRM minor management
 800  *  - DRM sysfs class
 801  *  - DRM debugfs root
 802  *
 803  * Furthermore, the DRM core provides dynamic char-dev lookups. For each
 804  * interface registered on a DRM device, you can request minor numbers from DRM
 805  * core. DRM core takes care of major-number management and char-dev
 806  * registration. A stub ->open() callback forwards any open() requests to the
 807  * registered minor.
 808  */
 809
 810 static int drm_stub_open(struct inode *inode, struct file *filp)
 811 {
 812         const struct file_operations *new_fops;
 813         struct drm_minor *minor;
 814         int err;
 815
 816         DRM_DEBUG("\n");
 817
 818         mutex_lock(&drm_global_mutex);
 819         minor = drm_minor_acquire(iminor(inode));
 820         if (IS_ERR(minor)) {
 821                 err = PTR_ERR(minor);
 822                 goto out_unlock;
 823         }
 824
 825         new_fops = fops_get(minor->dev->driver->fops);
 826         if (!new_fops) {
 827                 err = -ENODEV;
 828                 goto out_release;
 829         }
 830
 831         replace_fops(filp, new_fops);
 832         if (filp->f_op->open)
 833                 err = filp->f_op->open(inode, filp);
 834         else
 835                 err = 0;
 836
 837 out_release:
 838         drm_minor_release(minor);
 839 out_unlock:
 840         mutex_unlock(&drm_global_mutex);
 841         return err;
 842 }
 843
 844 static const struct file_operations drm_stub_fops = {
 845         .owner = THIS_MODULE,
 846         .open = drm_stub_open,
 847         .llseek = noop_llseek,
 848 };
 849
 850 static int __init drm_core_init(void)
 851 {
 852         int ret = -ENOMEM;
 853
 854         drm_global_init();
 855         drm_connector_ida_init();
 856         idr_init(&drm_minors_idr);
 857
 858         if (register_chrdev(DRM_MAJOR, "drm", &drm_stub_fops))
 859                 goto err_p1;
 860
 861         drm_class = drm_sysfs_create(THIS_MODULE, "drm");
 862         if (IS_ERR(drm_class)) {
 863                 printk(KERN_ERR "DRM: Error creating drm class.\n");
 864                 ret = PTR_ERR(drm_class);
 865                 goto err_p2;
 866         }
 867
 868         drm_debugfs_root = debugfs_create_dir("dri", NULL);
 869         if (!drm_debugfs_root) {
 870                 DRM_ERROR("Cannot create /sys/kernel/debug/dri\n");
 871                 ret = -1;
 872                 goto err_p3;
 873         }
 874
 875         DRM_INFO("Initialized %s %d.%d.%d %s\n",
 876                  CORE_NAME, CORE_MAJOR, CORE_MINOR, CORE_PATCHLEVEL, CORE_DATE);
 877         return 0;
 878 err_p3:
 879         drm_sysfs_destroy();
 880 err_p2:
 881         unregister_chrdev(DRM_MAJOR, "drm");
 882
 883         idr_destroy(&drm_minors_idr);
 884 err_p1:
 885         return ret;
 886 }
 887
 888 static void __exit drm_core_exit(void)
 889 {
 890         debugfs_remove(drm_debugfs_root);
 891         drm_sysfs_destroy();
 892
 893         unregister_chrdev(DRM_MAJOR, "drm");
 894
 895         drm_connector_ida_destroy();
 896         idr_destroy(&drm_minors_idr);
 897 }
 898
 899 module_init(drm_core_init);
 900 module_exit(drm_core_exit);