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 #define DRM_MAGIC_HASH_ORDER  4  /**< Size of key hash table. Must be power of 2. */
  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         if (drm_ht_create(&master->magiclist, DRM_MAGIC_HASH_ORDER)) {
 107                 kfree(master);
 108                 return NULL;
 109         }
 110         INIT_LIST_HEAD(&master->magicfree);
 111         master->minor = minor;
 112
 113         return master;
 114 }
 115
 116 struct drm_master *drm_master_get(struct drm_master *master)
 117 {
 118         kref_get(&master->refcount);
 119         return master;
 120 }
 121 EXPORT_SYMBOL(drm_master_get);
 122
 123 static void drm_master_destroy(struct kref *kref)
 124 {
 125         struct drm_master *master = container_of(kref, struct drm_master, refcount);
 126         struct drm_device *dev = master->minor->dev;
 127         struct drm_map_list *r_list, *list_temp;
 128
 129         mutex_lock(&dev->struct_mutex);
 130         if (dev->driver->master_destroy)
 131                 dev->driver->master_destroy(dev, master);
 132
 133         list_for_each_entry_safe(r_list, list_temp, &dev->maplist, head) {
 134                 if (r_list->master == master) {
 135                         drm_legacy_rmmap_locked(dev, r_list->map);
 136                         r_list = NULL;
 137                 }
 138         }
 139
 140         if (master->unique) {
 141                 kfree(master->unique);
 142                 master->unique = NULL;
 143                 master->unique_len = 0;
 144         }
 145
 146         drm_ht_remove(&master->magiclist);
 147
 148         mutex_unlock(&dev->struct_mutex);
 149         kfree(master);
 150 }
 151
 152 void drm_master_put(struct drm_master **master)
 153 {
 154         kref_put(&(*master)->refcount, drm_master_destroy);
 155         *master = NULL;
 156 }
 157 EXPORT_SYMBOL(drm_master_put);
 158
 159 int drm_setmaster_ioctl(struct drm_device *dev, void *data,
 160                         struct drm_file *file_priv)
 161 {
 162         int ret = 0;
 163
 164         mutex_lock(&dev->master_mutex);
 165         if (file_priv->is_master)
 166                 goto out_unlock;
 167
 168         if (file_priv->minor->master) {
 169                 ret = -EINVAL;
 170                 goto out_unlock;
 171         }
 172
 173         if (!file_priv->master) {
 174                 ret = -EINVAL;
 175                 goto out_unlock;
 176         }
 177
 178         file_priv->minor->master = drm_master_get(file_priv->master);
 179         file_priv->is_master = 1;
 180         if (dev->driver->master_set) {
 181                 ret = dev->driver->master_set(dev, file_priv, false);
 182                 if (unlikely(ret != 0)) {
 183                         file_priv->is_master = 0;
 184                         drm_master_put(&file_priv->minor->master);
 185                 }
 186         }
 187
 188 out_unlock:
 189         mutex_unlock(&dev->master_mutex);
 190         return ret;
 191 }
 192
 193 int drm_dropmaster_ioctl(struct drm_device *dev, void *data,
 194                          struct drm_file *file_priv)
 195 {
 196         int ret = -EINVAL;
 197
 198         mutex_lock(&dev->master_mutex);
 199         if (!file_priv->is_master)
 200                 goto out_unlock;
 201
 202         if (!file_priv->minor->master)
 203                 goto out_unlock;
 204
 205         ret = 0;
 206         if (dev->driver->master_drop)
 207                 dev->driver->master_drop(dev, file_priv, false);
 208         drm_master_put(&file_priv->minor->master);
 209         file_priv->is_master = 0;
 210
 211 out_unlock:
 212         mutex_unlock(&dev->master_mutex);
 213         return ret;
 214 }
 215
 216 /*
 217  * DRM Minors
 218  * A DRM device can provide several char-dev interfaces on the DRM-Major. Each
 219  * of them is represented by a drm_minor object. Depending on the capabilities
 220  * of the device-driver, different interfaces are registered.
 221  *
 222  * Minors can be accessed via dev->$minor_name. This pointer is either
 223  * NULL or a valid drm_minor pointer and stays valid as long as the device is
 224  * valid. This means, DRM minors have the same life-time as the underlying
 225  * device. However, this doesn't mean that the minor is active. Minors are
 226  * registered and unregistered dynamically according to device-state.
 227  */
 228
 229 static struct drm_minor **drm_minor_get_slot(struct drm_device *dev,
 230                                              unsigned int type)
 231 {
 232         switch (type) {
 233         case DRM_MINOR_LEGACY:
 234                 return &dev->primary;
 235         case DRM_MINOR_RENDER:
 236                 return &dev->render;
 237         case DRM_MINOR_CONTROL:
 238                 return &dev->control;
 239         default:
 240                 return NULL;
 241         }
 242 }
 243
 244 static int drm_minor_alloc(struct drm_device *dev, unsigned int type)
 245 {
 246         struct drm_minor *minor;
 247         unsigned long flags;
 248         int r;
 249
 250         minor = kzalloc(sizeof(*minor), GFP_KERNEL);
 251         if (!minor)
 252                 return -ENOMEM;
 253
 254         minor->type = type;
 255         minor->dev = dev;
 256
 257         idr_preload(GFP_KERNEL);
 258         spin_lock_irqsave(&drm_minor_lock, flags);
 259         r = idr_alloc(&drm_minors_idr,
 260                       NULL,
 261                       64 * type,
 262                       64 * (type + 1),
 263                       GFP_NOWAIT);
 264         spin_unlock_irqrestore(&drm_minor_lock, flags);
 265         idr_preload_end();
 266
 267         if (r < 0)
 268                 goto err_free;
 269
 270         minor->index = r;
 271
 272         minor->kdev = drm_sysfs_minor_alloc(minor);
 273         if (IS_ERR(minor->kdev)) {
 274                 r = PTR_ERR(minor->kdev);
 275                 goto err_index;
 276         }
 277
 278         *drm_minor_get_slot(dev, type) = minor;
 279         return 0;
 280
 281 err_index:
 282         spin_lock_irqsave(&drm_minor_lock, flags);
 283         idr_remove(&drm_minors_idr, minor->index);
 284         spin_unlock_irqrestore(&drm_minor_lock, flags);
 285 err_free:
 286         kfree(minor);
 287         return r;
 288 }
 289
 290 static void drm_minor_free(struct drm_device *dev, unsigned int type)
 291 {
 292         struct drm_minor **slot, *minor;
 293         unsigned long flags;
 294
 295         slot = drm_minor_get_slot(dev, type);
 296         minor = *slot;
 297         if (!minor)
 298                 return;
 299
 300         drm_mode_group_destroy(&minor->mode_group);
 301         put_device(minor->kdev);
 302
 303         spin_lock_irqsave(&drm_minor_lock, flags);
 304         idr_remove(&drm_minors_idr, minor->index);
 305         spin_unlock_irqrestore(&drm_minor_lock, flags);
 306
 307         kfree(minor);
 308         *slot = NULL;
 309 }
 310
 311 static int drm_minor_register(struct drm_device *dev, unsigned int type)
 312 {
 313         struct drm_minor *minor;
 314         unsigned long flags;
 315         int ret;
 316
 317         DRM_DEBUG("\n");
 318
 319         minor = *drm_minor_get_slot(dev, type);
 320         if (!minor)
 321                 return 0;
 322
 323         ret = drm_debugfs_init(minor, minor->index, drm_debugfs_root);
 324         if (ret) {
 325                 DRM_ERROR("DRM: Failed to initialize /sys/kernel/debug/dri.\n");
 326                 return ret;
 327         }
 328
 329         ret = device_add(minor->kdev);
 330         if (ret)
 331                 goto err_debugfs;
 332
 333         /* replace NULL with @minor so lookups will succeed from now on */
 334         spin_lock_irqsave(&drm_minor_lock, flags);
 335         idr_replace(&drm_minors_idr, minor, minor->index);
 336         spin_unlock_irqrestore(&drm_minor_lock, flags);
 337
 338         DRM_DEBUG("new minor registered %d\n", minor->index);
 339         return 0;
 340
 341 err_debugfs:
 342         drm_debugfs_cleanup(minor);
 343         return ret;
 344 }
 345
 346 static void drm_minor_unregister(struct drm_device *dev, unsigned int type)
 347 {
 348         struct drm_minor *minor;
 349         unsigned long flags;
 350
 351         minor = *drm_minor_get_slot(dev, type);
 352         if (!minor || !device_is_registered(minor->kdev))
 353                 return;
 354
 355         /* replace @minor with NULL so lookups will fail from now on */
 356         spin_lock_irqsave(&drm_minor_lock, flags);
 357         idr_replace(&drm_minors_idr, NULL, minor->index);
 358         spin_unlock_irqrestore(&drm_minor_lock, flags);
 359
 360         device_del(minor->kdev);
 361         dev_set_drvdata(minor->kdev, NULL); /* safety belt */
 362         drm_debugfs_cleanup(minor);
 363 }
 364
 365 /**
 366  * drm_minor_acquire - Acquire a DRM minor
 367  * @minor_id: Minor ID of the DRM-minor
 368  *
 369  * Looks up the given minor-ID and returns the respective DRM-minor object. The
 370  * refence-count of the underlying device is increased so you must release this
 371  * object with drm_minor_release().
 372  *
 373  * As long as you hold this minor, it is guaranteed that the object and the
 374  * minor->dev pointer will stay valid! However, the device may get unplugged and
 375  * unregistered while you hold the minor.
 376  *
 377  * Returns:
 378  * Pointer to minor-object with increased device-refcount, or PTR_ERR on
 379  * failure.
 380  */
 381 struct drm_minor *drm_minor_acquire(unsigned int minor_id)
 382 {
 383         struct drm_minor *minor;
 384         unsigned long flags;
 385
 386         spin_lock_irqsave(&drm_minor_lock, flags);
 387         minor = idr_find(&drm_minors_idr, minor_id);
 388         if (minor)
 389                 drm_dev_ref(minor->dev);
 390         spin_unlock_irqrestore(&drm_minor_lock, flags);
 391
 392         if (!minor) {
 393                 return ERR_PTR(-ENODEV);
 394         } else if (drm_device_is_unplugged(minor->dev)) {
 395                 drm_dev_unref(minor->dev);
 396                 return ERR_PTR(-ENODEV);
 397         }
 398
 399         return minor;
 400 }
 401
 402 /**
 403  * drm_minor_release - Release DRM minor
 404  * @minor: Pointer to DRM minor object
 405  *
 406  * Release a minor that was previously acquired via drm_minor_acquire().
 407  */
 408 void drm_minor_release(struct drm_minor *minor)
 409 {
 410         drm_dev_unref(minor->dev);
 411 }
 412
 413 /**
 414  * drm_put_dev - Unregister and release a DRM device
 415  * @dev: DRM device
 416  *
 417  * Called at module unload time or when a PCI device is unplugged.
 418  *
 419  * Use of this function is discouraged. It will eventually go away completely.
 420  * Please use drm_dev_unregister() and drm_dev_unref() explicitly instead.
 421  *
 422  * Cleans up all DRM device, calling drm_lastclose().
 423  */
 424 void drm_put_dev(struct drm_device *dev)
 425 {
 426         DRM_DEBUG("\n");
 427
 428         if (!dev) {
 429                 DRM_ERROR("cleanup called no dev\n");
 430                 return;
 431         }
 432
 433         drm_dev_unregister(dev);
 434         drm_dev_unref(dev);
 435 }
 436 EXPORT_SYMBOL(drm_put_dev);
 437
 438 void drm_unplug_dev(struct drm_device *dev)
 439 {
 440         /* for a USB device */
 441         drm_minor_unregister(dev, DRM_MINOR_LEGACY);
 442         drm_minor_unregister(dev, DRM_MINOR_RENDER);
 443         drm_minor_unregister(dev, DRM_MINOR_CONTROL);
 444
 445         mutex_lock(&drm_global_mutex);
 446
 447         drm_device_set_unplugged(dev);
 448
 449         if (dev->open_count == 0) {
 450                 drm_put_dev(dev);
 451         }
 452         mutex_unlock(&drm_global_mutex);
 453 }
 454 EXPORT_SYMBOL(drm_unplug_dev);
 455
 456 /*
 457  * DRM internal mount
 458  * We want to be able to allocate our own "struct address_space" to control
 459  * memory-mappings in VRAM (or stolen RAM, ...). However, core MM does not allow
 460  * stand-alone address_space objects, so we need an underlying inode. As there
 461  * is no way to allocate an independent inode easily, we need a fake internal
 462  * VFS mount-point.
 463  *
 464  * The drm_fs_inode_new() function allocates a new inode, drm_fs_inode_free()
 465  * frees it again. You are allowed to use iget() and iput() to get references to
 466  * the inode. But each drm_fs_inode_new() call must be paired with exactly one
 467  * drm_fs_inode_free() call (which does not have to be the last iput()).
 468  * We use drm_fs_inode_*() to manage our internal VFS mount-point and share it
 469  * between multiple inode-users. You could, technically, call
 470  * iget() + drm_fs_inode_free() directly after alloc and sometime later do an
 471  * iput(), but this way you'd end up with a new vfsmount for each inode.
 472  */
 473
 474 static int drm_fs_cnt;
 475 static struct vfsmount *drm_fs_mnt;
 476
 477 static const struct dentry_operations drm_fs_dops = {
 478         .d_dname        = simple_dname,
 479 };
 480
 481 static const struct super_operations drm_fs_sops = {
 482         .statfs         = simple_statfs,
 483 };
 484
 485 static struct dentry *drm_fs_mount(struct file_system_type *fs_type, int flags,
 486                                    const char *dev_name, void *data)
 487 {
 488         return mount_pseudo(fs_type,
 489                             "drm:",
 490                             &drm_fs_sops,
 491                             &drm_fs_dops,
 492                             0x010203ff);
 493 }
 494
 495 static struct file_system_type drm_fs_type = {
 496         .name           = "drm",
 497         .owner          = THIS_MODULE,
 498         .mount          = drm_fs_mount,
 499         .kill_sb        = kill_anon_super,
 500 };
 501
 502 static struct inode *drm_fs_inode_new(void)
 503 {
 504         struct inode *inode;
 505         int r;
 506
 507         r = simple_pin_fs(&drm_fs_type, &drm_fs_mnt, &drm_fs_cnt);
 508         if (r < 0) {
 509                 DRM_ERROR("Cannot mount pseudo fs: %d\n", r);
 510                 return ERR_PTR(r);
 511         }
 512
 513         inode = alloc_anon_inode(drm_fs_mnt->mnt_sb);
 514         if (IS_ERR(inode))
 515                 simple_release_fs(&drm_fs_mnt, &drm_fs_cnt);
 516
 517         return inode;
 518 }
 519
 520 static void drm_fs_inode_free(struct inode *inode)
 521 {
 522         if (inode) {
 523                 iput(inode);
 524                 simple_release_fs(&drm_fs_mnt, &drm_fs_cnt);
 525         }
 526 }
 527
 528 /**
 529  * drm_dev_alloc - Allocate new DRM device
 530  * @driver: DRM driver to allocate device for
 531  * @parent: Parent device object
 532  *
 533  * Allocate and initialize a new DRM device. No device registration is done.
 534  * Call drm_dev_register() to advertice the device to user space and register it
 535  * with other core subsystems.
 536  *
 537  * The initial ref-count of the object is 1. Use drm_dev_ref() and
 538  * drm_dev_unref() to take and drop further ref-counts.
 539  *
 540  * RETURNS:
 541  * Pointer to new DRM device, or NULL if out of memory.
 542  */
 543 struct drm_device *drm_dev_alloc(struct drm_driver *driver,
 544                                  struct device *parent)
 545 {
 546         struct drm_device *dev;
 547         int ret;
 548
 549         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 550         if (!dev)
 551                 return NULL;
 552
 553         kref_init(&dev->ref);
 554         dev->dev = parent;
 555         dev->driver = driver;
 556
 557         INIT_LIST_HEAD(&dev->filelist);
 558         INIT_LIST_HEAD(&dev->ctxlist);
 559         INIT_LIST_HEAD(&dev->vmalist);
 560         INIT_LIST_HEAD(&dev->maplist);
 561         INIT_LIST_HEAD(&dev->vblank_event_list);
 562
 563         spin_lock_init(&dev->buf_lock);
 564         spin_lock_init(&dev->event_lock);
 565         mutex_init(&dev->struct_mutex);
 566         mutex_init(&dev->ctxlist_mutex);
 567         mutex_init(&dev->master_mutex);
 568
 569         dev->anon_inode = drm_fs_inode_new();
 570         if (IS_ERR(dev->anon_inode)) {
 571                 ret = PTR_ERR(dev->anon_inode);
 572                 DRM_ERROR("Cannot allocate anonymous inode: %d\n", ret);
 573                 goto err_free;
 574         }
 575
 576         if (drm_core_check_feature(dev, DRIVER_MODESET)) {
 577                 ret = drm_minor_alloc(dev, DRM_MINOR_CONTROL);
 578                 if (ret)
 579                         goto err_minors;
 580         }
 581
 582         if (drm_core_check_feature(dev, DRIVER_RENDER)) {
 583                 ret = drm_minor_alloc(dev, DRM_MINOR_RENDER);
 584                 if (ret)
 585                         goto err_minors;
 586         }
 587
 588         ret = drm_minor_alloc(dev, DRM_MINOR_LEGACY);
 589         if (ret)
 590                 goto err_minors;
 591
 592         if (drm_ht_create(&dev->map_hash, 12))
 593                 goto err_minors;
 594
 595         ret = drm_legacy_ctxbitmap_init(dev);
 596         if (ret) {
 597                 DRM_ERROR("Cannot allocate memory for context bitmap.\n");
 598                 goto err_ht;
 599         }
 600
 601         if (driver->driver_features & DRIVER_GEM) {
 602                 ret = drm_gem_init(dev);
 603                 if (ret) {
 604                         DRM_ERROR("Cannot initialize graphics execution manager (GEM)\n");
 605                         goto err_ctxbitmap;
 606                 }
 607         }
 608
 609         return dev;
 610
 611 err_ctxbitmap:
 612         drm_legacy_ctxbitmap_cleanup(dev);
 613 err_ht:
 614         drm_ht_remove(&dev->map_hash);
 615 err_minors:
 616         drm_minor_free(dev, DRM_MINOR_LEGACY);
 617         drm_minor_free(dev, DRM_MINOR_RENDER);
 618         drm_minor_free(dev, DRM_MINOR_CONTROL);
 619         drm_fs_inode_free(dev->anon_inode);
 620 err_free:
 621         mutex_destroy(&dev->master_mutex);
 622         kfree(dev);
 623         return NULL;
 624 }
 625 EXPORT_SYMBOL(drm_dev_alloc);
 626
 627 static void drm_dev_release(struct kref *ref)
 628 {
 629         struct drm_device *dev = container_of(ref, struct drm_device, ref);
 630
 631         if (dev->driver->driver_features & DRIVER_GEM)
 632                 drm_gem_destroy(dev);
 633
 634         drm_legacy_ctxbitmap_cleanup(dev);
 635         drm_ht_remove(&dev->map_hash);
 636         drm_fs_inode_free(dev->anon_inode);
 637
 638         drm_minor_free(dev, DRM_MINOR_LEGACY);
 639         drm_minor_free(dev, DRM_MINOR_RENDER);
 640         drm_minor_free(dev, DRM_MINOR_CONTROL);
 641
 642         mutex_destroy(&dev->master_mutex);
 643         kfree(dev->unique);
 644         kfree(dev);
 645 }
 646
 647 /**
 648  * drm_dev_ref - Take reference of a DRM device
 649  * @dev: device to take reference of or NULL
 650  *
 651  * This increases the ref-count of @dev by one. You *must* already own a
 652  * reference when calling this. Use drm_dev_unref() to drop this reference
 653  * again.
 654  *
 655  * This function never fails. However, this function does not provide *any*
 656  * guarantee whether the device is alive or running. It only provides a
 657  * reference to the object and the memory associated with it.
 658  */
 659 void drm_dev_ref(struct drm_device *dev)
 660 {
 661         if (dev)
 662                 kref_get(&dev->ref);
 663 }
 664 EXPORT_SYMBOL(drm_dev_ref);
 665
 666 /**
 667  * drm_dev_unref - Drop reference of a DRM device
 668  * @dev: device to drop reference of or NULL
 669  *
 670  * This decreases the ref-count of @dev by one. The device is destroyed if the
 671  * ref-count drops to zero.
 672  */
 673 void drm_dev_unref(struct drm_device *dev)
 674 {
 675         if (dev)
 676                 kref_put(&dev->ref, drm_dev_release);
 677 }
 678 EXPORT_SYMBOL(drm_dev_unref);
 679
 680 /**
 681  * drm_dev_register - Register DRM device
 682  * @dev: Device to register
 683  * @flags: Flags passed to the driver's .load() function
 684  *
 685  * Register the DRM device @dev with the system, advertise device to user-space
 686  * and start normal device operation. @dev must be allocated via drm_dev_alloc()
 687  * previously.
 688  *
 689  * Never call this twice on any device!
 690  *
 691  * RETURNS:
 692  * 0 on success, negative error code on failure.
 693  */
 694 int drm_dev_register(struct drm_device *dev, unsigned long flags)
 695 {
 696         int ret;
 697
 698         mutex_lock(&drm_global_mutex);
 699
 700         ret = drm_minor_register(dev, DRM_MINOR_CONTROL);
 701         if (ret)
 702                 goto err_minors;
 703
 704         ret = drm_minor_register(dev, DRM_MINOR_RENDER);
 705         if (ret)
 706                 goto err_minors;
 707
 708         ret = drm_minor_register(dev, DRM_MINOR_LEGACY);
 709         if (ret)
 710                 goto err_minors;
 711
 712         if (dev->driver->load) {
 713                 ret = dev->driver->load(dev, flags);
 714                 if (ret)
 715                         goto err_minors;
 716         }
 717
 718         /* setup grouping for legacy outputs */
 719         if (drm_core_check_feature(dev, DRIVER_MODESET)) {
 720                 ret = drm_mode_group_init_legacy_group(dev,
 721                                 &dev->primary->mode_group);
 722                 if (ret)
 723                         goto err_unload;
 724         }
 725
 726         ret = 0;
 727         goto out_unlock;
 728
 729 err_unload:
 730         if (dev->driver->unload)
 731                 dev->driver->unload(dev);
 732 err_minors:
 733         drm_minor_unregister(dev, DRM_MINOR_LEGACY);
 734         drm_minor_unregister(dev, DRM_MINOR_RENDER);
 735         drm_minor_unregister(dev, DRM_MINOR_CONTROL);
 736 out_unlock:
 737         mutex_unlock(&drm_global_mutex);
 738         return ret;
 739 }
 740 EXPORT_SYMBOL(drm_dev_register);
 741
 742 /**
 743  * drm_dev_unregister - Unregister DRM device
 744  * @dev: Device to unregister
 745  *
 746  * Unregister the DRM device from the system. This does the reverse of
 747  * drm_dev_register() but does not deallocate the device. The caller must call
 748  * drm_dev_unref() to drop their final reference.
 749  */
 750 void drm_dev_unregister(struct drm_device *dev)
 751 {
 752         struct drm_map_list *r_list, *list_temp;
 753
 754         drm_lastclose(dev);
 755
 756         if (dev->driver->unload)
 757                 dev->driver->unload(dev);
 758
 759         if (dev->agp)
 760                 drm_pci_agp_destroy(dev);
 761
 762         drm_vblank_cleanup(dev);
 763
 764         list_for_each_entry_safe(r_list, list_temp, &dev->maplist, head)
 765                 drm_legacy_rmmap(dev, r_list->map);
 766
 767         drm_minor_unregister(dev, DRM_MINOR_LEGACY);
 768         drm_minor_unregister(dev, DRM_MINOR_RENDER);
 769         drm_minor_unregister(dev, DRM_MINOR_CONTROL);
 770 }
 771 EXPORT_SYMBOL(drm_dev_unregister);
 772
 773 /**
 774  * drm_dev_set_unique - Set the unique name of a DRM device
 775  * @dev: device of which to set the unique name
 776  * @fmt: format string for unique name
 777  *
 778  * Sets the unique name of a DRM device using the specified format string and
 779  * a variable list of arguments. Drivers can use this at driver probe time if
 780  * the unique name of the devices they drive is static.
 781  *
 782  * Return: 0 on success or a negative error code on failure.
 783  */
 784 int drm_dev_set_unique(struct drm_device *dev, const char *fmt, ...)
 785 {
 786         va_list ap;
 787
 788         kfree(dev->unique);
 789
 790         va_start(ap, fmt);
 791         dev->unique = kvasprintf(GFP_KERNEL, fmt, ap);
 792         va_end(ap);
 793
 794         return dev->unique ? 0 : -ENOMEM;
 795 }
 796 EXPORT_SYMBOL(drm_dev_set_unique);
 797
 798 /*
 799  * DRM Core
 800  * The DRM core module initializes all global DRM objects and makes them
 801  * available to drivers. Once setup, drivers can probe their respective
 802  * devices.
 803  * Currently, core management includes:
 804  *  - The "DRM-Global" key/value database
 805  *  - Global ID management for connectors
 806  *  - DRM major number allocation
 807  *  - DRM minor management
 808  *  - DRM sysfs class
 809  *  - DRM debugfs root
 810  *
 811  * Furthermore, the DRM core provides dynamic char-dev lookups. For each
 812  * interface registered on a DRM device, you can request minor numbers from DRM
 813  * core. DRM core takes care of major-number management and char-dev
 814  * registration. A stub ->open() callback forwards any open() requests to the
 815  * registered minor.
 816  */
 817
 818 static int drm_stub_open(struct inode *inode, struct file *filp)
 819 {
 820         const struct file_operations *new_fops;
 821         struct drm_minor *minor;
 822         int err;
 823
 824         DRM_DEBUG("\n");
 825
 826         mutex_lock(&drm_global_mutex);
 827         minor = drm_minor_acquire(iminor(inode));
 828         if (IS_ERR(minor)) {
 829                 err = PTR_ERR(minor);
 830                 goto out_unlock;
 831         }
 832
 833         new_fops = fops_get(minor->dev->driver->fops);
 834         if (!new_fops) {
 835                 err = -ENODEV;
 836                 goto out_release;
 837         }
 838
 839         replace_fops(filp, new_fops);
 840         if (filp->f_op->open)
 841                 err = filp->f_op->open(inode, filp);
 842         else
 843                 err = 0;
 844
 845 out_release:
 846         drm_minor_release(minor);
 847 out_unlock:
 848         mutex_unlock(&drm_global_mutex);
 849         return err;
 850 }
 851
 852 static const struct file_operations drm_stub_fops = {
 853         .owner = THIS_MODULE,
 854         .open = drm_stub_open,
 855         .llseek = noop_llseek,
 856 };
 857
 858 static int __init drm_core_init(void)
 859 {
 860         int ret = -ENOMEM;
 861
 862         drm_global_init();
 863         drm_connector_ida_init();
 864         idr_init(&drm_minors_idr);
 865
 866         if (register_chrdev(DRM_MAJOR, "drm", &drm_stub_fops))
 867                 goto err_p1;
 868
 869         drm_class = drm_sysfs_create(THIS_MODULE, "drm");
 870         if (IS_ERR(drm_class)) {
 871                 printk(KERN_ERR "DRM: Error creating drm class.\n");
 872                 ret = PTR_ERR(drm_class);
 873                 goto err_p2;
 874         }
 875
 876         drm_debugfs_root = debugfs_create_dir("dri", NULL);
 877         if (!drm_debugfs_root) {
 878                 DRM_ERROR("Cannot create /sys/kernel/debug/dri\n");
 879                 ret = -1;
 880                 goto err_p3;
 881         }
 882
 883         DRM_INFO("Initialized %s %d.%d.%d %s\n",
 884                  CORE_NAME, CORE_MAJOR, CORE_MINOR, CORE_PATCHLEVEL, CORE_DATE);
 885         return 0;
 886 err_p3:
 887         drm_sysfs_destroy();
 888 err_p2:
 889         unregister_chrdev(DRM_MAJOR, "drm");
 890
 891         idr_destroy(&drm_minors_idr);
 892 err_p1:
 893         return ret;
 894 }
 895
 896 static void __exit drm_core_exit(void)
 897 {
 898         debugfs_remove(drm_debugfs_root);
 899         drm_sysfs_destroy();
 900
 901         unregister_chrdev(DRM_MAJOR, "drm");
 902
 903         drm_connector_ida_destroy();
 904         idr_destroy(&drm_minors_idr);
 905 }
 906
 907 module_init(drm_core_init);
 908 module_exit(drm_core_exit);