drivers/gpu/drm/drm_fops.c

   1 /**
   2  * \file drm_fops.c
   3  * File operations for DRM
   4  *
   5  * \author Rickard E. (Rik) Faith <faith@valinux.com>
   6  * \author Daryll Strauss <daryll@valinux.com>
   7  * \author Gareth Hughes <gareth@valinux.com>
   8  */
   9
  10 /*
  11  * Created: Mon Jan  4 08:58:31 1999 by faith@valinux.com
  12  *
  13  * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
  14  * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
  15  * All Rights Reserved.
  16  *
  17  * Permission is hereby granted, free of charge, to any person obtaining a
  18  * copy of this software and associated documentation files (the "Software"),
  19  * to deal in the Software without restriction, including without limitation
  20  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  21  * and/or sell copies of the Software, and to permit persons to whom the
  22  * Software is furnished to do so, subject to the following conditions:
  23  *
  24  * The above copyright notice and this permission notice (including the next
  25  * paragraph) shall be included in all copies or substantial portions of the
  26  * Software.
  27  *
  28  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  29  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  30  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  31  * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  32  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  33  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  34  * OTHER DEALINGS IN THE SOFTWARE.
  35  */
  36
  37 #include <drm/drmP.h>
  38 #include <linux/poll.h>
  39 #include <linux/slab.h>
  40 #include <linux/module.h>
  41
  42 /* from BKL pushdown */
  43 DEFINE_MUTEX(drm_global_mutex);
  44 EXPORT_SYMBOL(drm_global_mutex);
  45
  46 static int drm_open_helper(struct file *filp, struct drm_minor *minor);
  47
  48 static int drm_setup(struct drm_device * dev)
  49 {
  50         int ret;
  51
  52         if (dev->driver->firstopen &&
  53             !drm_core_check_feature(dev, DRIVER_MODESET)) {
  54                 ret = dev->driver->firstopen(dev);
  55                 if (ret != 0)
  56                         return ret;
  57         }
  58
  59         ret = drm_legacy_dma_setup(dev);
  60         if (ret < 0)
  61                 return ret;
  62
  63
  64         DRM_DEBUG("\n");
  65         return 0;
  66 }
  67
  68 /**
  69  * Open file.
  70  *
  71  * \param inode device inode
  72  * \param filp file pointer.
  73  * \return zero on success or a negative number on failure.
  74  *
  75  * Searches the DRM device with the same minor number, calls open_helper(), and
  76  * increments the device open count. If the open count was previous at zero,
  77  * i.e., it's the first that the device is open, then calls setup().
  78  */
  79 int drm_open(struct inode *inode, struct file *filp)
  80 {
  81         struct drm_device *dev;
  82         struct drm_minor *minor;
  83         int retcode;
  84         int need_setup = 0;
  85
  86         minor = drm_minor_acquire(iminor(inode));
  87         if (IS_ERR(minor))
  88                 return PTR_ERR(minor);
  89
  90         dev = minor->dev;
  91         if (!dev->open_count++)
  92                 need_setup = 1;
  93
  94         /* share address_space across all char-devs of a single device */
  95         filp->f_mapping = dev->anon_inode->i_mapping;
  96
  97         retcode = drm_open_helper(filp, minor);
  98         if (retcode)
  99                 goto err_undo;
 100         if (need_setup) {
 101                 retcode = drm_setup(dev);
 102                 if (retcode)
 103                         goto err_undo;
 104         }
 105         return 0;
 106
 107 err_undo:
 108         dev->open_count--;
 109         drm_minor_release(minor);
 110         return retcode;
 111 }
 112 EXPORT_SYMBOL(drm_open);
 113
 114 /**
 115  * Check whether DRI will run on this CPU.
 116  *
 117  * \return non-zero if the DRI will run on this CPU, or zero otherwise.
 118  */
 119 static int drm_cpu_valid(void)
 120 {
 121 #if defined(__sparc__) && !defined(__sparc_v9__)
 122         return 0;               /* No cmpxchg before v9 sparc. */
 123 #endif
 124         return 1;
 125 }
 126
 127 /**
 128  * Called whenever a process opens /dev/drm.
 129  *
 130  * \param filp file pointer.
 131  * \param minor acquired minor-object.
 132  * \return zero on success or a negative number on failure.
 133  *
 134  * Creates and initializes a drm_file structure for the file private data in \p
 135  * filp and add it into the double linked list in \p dev.
 136  */
 137 static int drm_open_helper(struct file *filp, struct drm_minor *minor)
 138 {
 139         struct drm_device *dev = minor->dev;
 140         struct drm_file *priv;
 141         int ret;
 142
 143         if (filp->f_flags & O_EXCL)
 144                 return -EBUSY;  /* No exclusive opens */
 145         if (!drm_cpu_valid())
 146                 return -EINVAL;
 147         if (dev->switch_power_state != DRM_SWITCH_POWER_ON && dev->switch_power_state != DRM_SWITCH_POWER_DYNAMIC_OFF)
 148                 return -EINVAL;
 149
 150         DRM_DEBUG("pid = %d, minor = %d\n", task_pid_nr(current), minor->index);
 151
 152         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 153         if (!priv)
 154                 return -ENOMEM;
 155
 156         filp->private_data = priv;
 157         priv->filp = filp;
 158         priv->uid = current_euid();
 159         priv->pid = get_pid(task_pid(current));
 160         priv->minor = minor;
 161
 162         /* for compatibility root is always authenticated */
 163         priv->authenticated = capable(CAP_SYS_ADMIN);
 164         priv->lock_count = 0;
 165
 166         INIT_LIST_HEAD(&priv->lhead);
 167         INIT_LIST_HEAD(&priv->fbs);
 168         mutex_init(&priv->fbs_lock);
 169         INIT_LIST_HEAD(&priv->event_list);
 170         init_waitqueue_head(&priv->event_wait);
 171         priv->event_space = 4096; /* set aside 4k for event buffer */
 172
 173         if (dev->driver->driver_features & DRIVER_GEM)
 174                 drm_gem_open(dev, priv);
 175
 176         if (drm_core_check_feature(dev, DRIVER_PRIME))
 177                 drm_prime_init_file_private(&priv->prime);
 178
 179         if (dev->driver->open) {
 180                 ret = dev->driver->open(dev, priv);
 181                 if (ret < 0)
 182                         goto out_prime_destroy;
 183         }
 184
 185         /* if there is no current master make this fd it, but do not create
 186          * any master object for render clients */
 187         mutex_lock(&dev->master_mutex);
 188         if (drm_is_primary_client(priv) && !priv->minor->master) {
 189                 /* create a new master */
 190                 priv->minor->master = drm_master_create(priv->minor);
 191                 if (!priv->minor->master) {
 192                         ret = -ENOMEM;
 193                         goto out_close;
 194                 }
 195
 196                 /* take another reference for the copy in the local file priv */
 197                 priv->master = drm_master_get(priv->minor->master);
 198                 priv->authenticated = 1;
 199
 200                 if (dev->driver->master_create) {
 201                         ret = dev->driver->master_create(dev, priv->master);
 202                         if (ret) {
 203                                 /* drop both references if this fails */
 204                                 drm_master_put(&priv->minor->master);
 205                                 drm_master_put(&priv->master);
 206                                 goto out_close;
 207                         }
 208                 }
 209                 if (dev->driver->master_set) {
 210                         ret = dev->driver->master_set(dev, priv, true);
 211                         if (ret) {
 212                                 /* drop both references if this fails */
 213                                 drm_master_put(&priv->minor->master);
 214                                 drm_master_put(&priv->master);
 215                                 goto out_close;
 216                         }
 217                 }
 218         } else if (drm_is_primary_client(priv)) {
 219                 /* get a reference to the master */
 220                 priv->master = drm_master_get(priv->minor->master);
 221         }
 222         mutex_unlock(&dev->master_mutex);
 223
 224         mutex_lock(&dev->struct_mutex);
 225         list_add(&priv->lhead, &dev->filelist);
 226         mutex_unlock(&dev->struct_mutex);
 227
 228 #ifdef __alpha__
 229         /*
 230          * Default the hose
 231          */
 232         if (!dev->hose) {
 233                 struct pci_dev *pci_dev;
 234                 pci_dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
 235                 if (pci_dev) {
 236                         dev->hose = pci_dev->sysdata;
 237                         pci_dev_put(pci_dev);
 238                 }
 239                 if (!dev->hose) {
 240                         struct pci_bus *b = list_entry(pci_root_buses.next,
 241                                 struct pci_bus, node);
 242                         if (b)
 243                                 dev->hose = b->sysdata;
 244                 }
 245         }
 246 #endif
 247
 248         return 0;
 249
 250 out_close:
 251         mutex_unlock(&dev->master_mutex);
 252         if (dev->driver->postclose)
 253                 dev->driver->postclose(dev, priv);
 254 out_prime_destroy:
 255         if (drm_core_check_feature(dev, DRIVER_PRIME))
 256                 drm_prime_destroy_file_private(&priv->prime);
 257         if (dev->driver->driver_features & DRIVER_GEM)
 258                 drm_gem_release(dev, priv);
 259         put_pid(priv->pid);
 260         kfree(priv);
 261         filp->private_data = NULL;
 262         return ret;
 263 }
 264
 265 static void drm_master_release(struct drm_device *dev, struct file *filp)
 266 {
 267         struct drm_file *file_priv = filp->private_data;
 268
 269         if (drm_i_have_hw_lock(dev, file_priv)) {
 270                 DRM_DEBUG("File %p released, freeing lock for context %d\n",
 271                           filp, _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
 272                 drm_lock_free(&file_priv->master->lock,
 273                               _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
 274         }
 275 }
 276
 277 static void drm_events_release(struct drm_file *file_priv)
 278 {
 279         struct drm_device *dev = file_priv->minor->dev;
 280         struct drm_pending_event *e, *et;
 281         struct drm_pending_vblank_event *v, *vt;
 282         unsigned long flags;
 283
 284         spin_lock_irqsave(&dev->event_lock, flags);
 285
 286         /* Remove pending flips */
 287         list_for_each_entry_safe(v, vt, &dev->vblank_event_list, base.link)
 288                 if (v->base.file_priv == file_priv) {
 289                         list_del(&v->base.link);
 290                         drm_vblank_put(dev, v->pipe);
 291                         v->base.destroy(&v->base);
 292                 }
 293
 294         /* Remove unconsumed events */
 295         list_for_each_entry_safe(e, et, &file_priv->event_list, link) {
 296                 list_del(&e->link);
 297                 e->destroy(e);
 298         }
 299
 300         spin_unlock_irqrestore(&dev->event_lock, flags);
 301 }
 302
 303 /**
 304  * drm_legacy_dev_reinit
 305  *
 306  * Reinitializes a legacy/ums drm device in it's lastclose function.
 307  */
 308 static void drm_legacy_dev_reinit(struct drm_device *dev)
 309 {
 310         if (drm_core_check_feature(dev, DRIVER_MODESET))
 311                 return;
 312
 313         dev->sigdata.lock = NULL;
 314
 315         dev->context_flag = 0;
 316         dev->last_context = 0;
 317         dev->if_version = 0;
 318 }
 319
 320 /**
 321  * Take down the DRM device.
 322  *
 323  * \param dev DRM device structure.
 324  *
 325  * Frees every resource in \p dev.
 326  *
 327  * \sa drm_device
 328  */
 329 int drm_lastclose(struct drm_device * dev)
 330 {
 331         struct drm_vma_entry *vma, *vma_temp;
 332
 333         DRM_DEBUG("\n");
 334
 335         if (dev->driver->lastclose)
 336                 dev->driver->lastclose(dev);
 337         DRM_DEBUG("driver lastclose completed\n");
 338
 339         if (dev->irq_enabled && !drm_core_check_feature(dev, DRIVER_MODESET))
 340                 drm_irq_uninstall(dev);
 341
 342         mutex_lock(&dev->struct_mutex);
 343
 344         drm_agp_clear(dev);
 345
 346         drm_legacy_sg_cleanup(dev);
 347
 348         /* Clear vma list (only built for debugging) */
 349         list_for_each_entry_safe(vma, vma_temp, &dev->vmalist, head) {
 350                 list_del(&vma->head);
 351                 kfree(vma);
 352         }
 353
 354         drm_legacy_dma_takedown(dev);
 355
 356         mutex_unlock(&dev->struct_mutex);
 357
 358         drm_legacy_dev_reinit(dev);
 359
 360         DRM_DEBUG("lastclose completed\n");
 361         return 0;
 362 }
 363
 364 /**
 365  * Release file.
 366  *
 367  * \param inode device inode
 368  * \param file_priv DRM file private.
 369  * \return zero on success or a negative number on failure.
 370  *
 371  * If the hardware lock is held then free it, and take it again for the kernel
 372  * context since it's necessary to reclaim buffers. Unlink the file private
 373  * data from its list and free it. Decreases the open count and if it reaches
 374  * zero calls drm_lastclose().
 375  */
 376 int drm_release(struct inode *inode, struct file *filp)
 377 {
 378         struct drm_file *file_priv = filp->private_data;
 379         struct drm_minor *minor = file_priv->minor;
 380         struct drm_device *dev = minor->dev;
 381         int retcode = 0;
 382
 383         mutex_lock(&drm_global_mutex);
 384
 385         DRM_DEBUG("open_count = %d\n", dev->open_count);
 386
 387         if (dev->driver->preclose)
 388                 dev->driver->preclose(dev, file_priv);
 389
 390         /* ========================================================
 391          * Begin inline drm_release
 392          */
 393
 394         DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
 395                   task_pid_nr(current),
 396                   (long)old_encode_dev(file_priv->minor->kdev->devt),
 397                   dev->open_count);
 398
 399         /* Release any auth tokens that might point to this file_priv,
 400            (do that under the drm_global_mutex) */
 401         if (file_priv->magic)
 402                 (void) drm_remove_magic(file_priv->master, file_priv->magic);
 403
 404         /* if the master has gone away we can't do anything with the lock */
 405         if (file_priv->minor->master)
 406                 drm_master_release(dev, filp);
 407
 408         if (drm_core_check_feature(dev, DRIVER_HAVE_DMA))
 409                 drm_core_reclaim_buffers(dev, file_priv);
 410
 411         drm_events_release(file_priv);
 412
 413         if (dev->driver->driver_features & DRIVER_MODESET)
 414                 drm_fb_release(file_priv);
 415
 416         if (dev->driver->driver_features & DRIVER_GEM)
 417                 drm_gem_release(dev, file_priv);
 418
 419         drm_ctxbitmap_flush(dev, file_priv);
 420
 421         mutex_lock(&dev->master_mutex);
 422
 423         if (drm_is_master(file_priv)) {
 424                 struct drm_master *master = file_priv->master;
 425
 426                 /**
 427                  * Since the master is disappearing, so is the
 428                  * possibility to lock.
 429                  */
 430                 mutex_lock(&dev->struct_mutex);
 431                 if (master->lock.hw_lock) {
 432                         if (dev->sigdata.lock == master->lock.hw_lock)
 433                                 dev->sigdata.lock = NULL;
 434                         master->lock.hw_lock = NULL;
 435                         master->lock.file_priv = NULL;
 436                         wake_up_interruptible_all(&master->lock.lock_queue);
 437                 }
 438                 mutex_unlock(&dev->struct_mutex);
 439
 440                 if (file_priv->minor->master == file_priv->master) {
 441                         /* drop the reference held my the minor */
 442                         if (dev->driver->master_drop)
 443                                 dev->driver->master_drop(dev, file_priv, true);
 444                         drm_master_put(&file_priv->minor->master);
 445                 }
 446         }
 447
 448         /* drop the master reference held by the file priv */
 449         if (file_priv->master)
 450                 drm_master_put(&file_priv->master);
 451         mutex_unlock(&dev->master_mutex);
 452
 453         mutex_lock(&dev->struct_mutex);
 454         list_del(&file_priv->lhead);
 455         mutex_unlock(&dev->struct_mutex);
 456
 457         if (dev->driver->postclose)
 458                 dev->driver->postclose(dev, file_priv);
 459
 460
 461         if (drm_core_check_feature(dev, DRIVER_PRIME))
 462                 drm_prime_destroy_file_private(&file_priv->prime);
 463
 464         put_pid(file_priv->pid);
 465         kfree(file_priv);
 466
 467         /* ========================================================
 468          * End inline drm_release
 469          */
 470
 471         if (!--dev->open_count) {
 472                 retcode = drm_lastclose(dev);
 473                 if (drm_device_is_unplugged(dev))
 474                         drm_put_dev(dev);
 475         }
 476         mutex_unlock(&drm_global_mutex);
 477
 478         drm_minor_release(minor);
 479
 480         return retcode;
 481 }
 482 EXPORT_SYMBOL(drm_release);
 483
 484 static bool
 485 drm_dequeue_event(struct drm_file *file_priv,
 486                   size_t total, size_t max, struct drm_pending_event **out)
 487 {
 488         struct drm_device *dev = file_priv->minor->dev;
 489         struct drm_pending_event *e;
 490         unsigned long flags;
 491         bool ret = false;
 492
 493         spin_lock_irqsave(&dev->event_lock, flags);
 494
 495         *out = NULL;
 496         if (list_empty(&file_priv->event_list))
 497                 goto out;
 498         e = list_first_entry(&file_priv->event_list,
 499                              struct drm_pending_event, link);
 500         if (e->event->length + total > max)
 501                 goto out;
 502
 503         file_priv->event_space += e->event->length;
 504         list_del(&e->link);
 505         *out = e;
 506         ret = true;
 507
 508 out:
 509         spin_unlock_irqrestore(&dev->event_lock, flags);
 510         return ret;
 511 }
 512
 513 ssize_t drm_read(struct file *filp, char __user *buffer,
 514                  size_t count, loff_t *offset)
 515 {
 516         struct drm_file *file_priv = filp->private_data;
 517         struct drm_pending_event *e;
 518         size_t total;
 519         ssize_t ret;
 520
 521         ret = wait_event_interruptible(file_priv->event_wait,
 522                                        !list_empty(&file_priv->event_list));
 523         if (ret < 0)
 524                 return ret;
 525
 526         total = 0;
 527         while (drm_dequeue_event(file_priv, total, count, &e)) {
 528                 if (copy_to_user(buffer + total,
 529                                  e->event, e->event->length)) {
 530                         total = -EFAULT;
 531                         break;
 532                 }
 533
 534                 total += e->event->length;
 535                 e->destroy(e);
 536         }
 537
 538         return total;
 539 }
 540 EXPORT_SYMBOL(drm_read);
 541
 542 unsigned int drm_poll(struct file *filp, struct poll_table_struct *wait)
 543 {
 544         struct drm_file *file_priv = filp->private_data;
 545         unsigned int mask = 0;
 546
 547         poll_wait(filp, &file_priv->event_wait, wait);
 548
 549         if (!list_empty(&file_priv->event_list))
 550                 mask |= POLLIN | POLLRDNORM;
 551
 552         return mask;
 553 }
 554 EXPORT_SYMBOL(drm_poll);