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: note that nothing else serializes idr_find() */
  43 DEFINE_MUTEX(drm_global_mutex);
  44 EXPORT_SYMBOL(drm_global_mutex);
  45
  46 static int drm_open_helper(struct inode *inode, struct file *filp,
  47                            struct drm_device * dev);
  48
  49 static int drm_setup(struct drm_device * dev)
  50 {
  51         int ret;
  52
  53         if (dev->driver->firstopen &&
  54             !drm_core_check_feature(dev, DRIVER_MODESET)) {
  55                 ret = dev->driver->firstopen(dev);
  56                 if (ret != 0)
  57                         return ret;
  58         }
  59
  60         ret = drm_legacy_dma_setup(dev);
  61         if (ret < 0)
  62                 return ret;
  63
  64
  65         DRM_DEBUG("\n");
  66         return 0;
  67 }
  68
  69 /**
  70  * Open file.
  71  *
  72  * \param inode device inode
  73  * \param filp file pointer.
  74  * \return zero on success or a negative number on failure.
  75  *
  76  * Searches the DRM device with the same minor number, calls open_helper(), and
  77  * increments the device open count. If the open count was previous at zero,
  78  * i.e., it's the first that the device is open, then calls setup().
  79  */
  80 int drm_open(struct inode *inode, struct file *filp)
  81 {
  82         struct drm_device *dev = NULL;
  83         int minor_id = iminor(inode);
  84         struct drm_minor *minor;
  85         int retcode = 0;
  86         int need_setup = 0;
  87         struct address_space *old_mapping;
  88         struct address_space *old_imapping;
  89
  90         minor = idr_find(&drm_minors_idr, minor_id);
  91         if (!minor)
  92                 return -ENODEV;
  93
  94         if (!(dev = minor->dev))
  95                 return -ENODEV;
  96
  97         if (drm_device_is_unplugged(dev))
  98                 return -ENODEV;
  99
 100         if (!dev->open_count++)
 101                 need_setup = 1;
 102         mutex_lock(&dev->struct_mutex);
 103         old_imapping = inode->i_mapping;
 104         old_mapping = dev->dev_mapping;
 105         if (old_mapping == NULL)
 106                 dev->dev_mapping = &inode->i_data;
 107         /* ihold ensures nobody can remove inode with our i_data */
 108         ihold(container_of(dev->dev_mapping, struct inode, i_data));
 109         inode->i_mapping = dev->dev_mapping;
 110         filp->f_mapping = dev->dev_mapping;
 111         mutex_unlock(&dev->struct_mutex);
 112
 113         retcode = drm_open_helper(inode, filp, dev);
 114         if (retcode)
 115                 goto err_undo;
 116         if (need_setup) {
 117                 retcode = drm_setup(dev);
 118                 if (retcode)
 119                         goto err_undo;
 120         }
 121         return 0;
 122
 123 err_undo:
 124         mutex_lock(&dev->struct_mutex);
 125         filp->f_mapping = old_imapping;
 126         inode->i_mapping = old_imapping;
 127         iput(container_of(dev->dev_mapping, struct inode, i_data));
 128         dev->dev_mapping = old_mapping;
 129         mutex_unlock(&dev->struct_mutex);
 130         dev->open_count--;
 131         return retcode;
 132 }
 133 EXPORT_SYMBOL(drm_open);
 134
 135 /**
 136  * File \c open operation.
 137  *
 138  * \param inode device inode.
 139  * \param filp file pointer.
 140  *
 141  * Puts the dev->fops corresponding to the device minor number into
 142  * \p filp, call the \c open method, and restore the file operations.
 143  */
 144 int drm_stub_open(struct inode *inode, struct file *filp)
 145 {
 146         struct drm_device *dev = NULL;
 147         struct drm_minor *minor;
 148         int minor_id = iminor(inode);
 149         int err = -ENODEV;
 150         const struct file_operations *new_fops;
 151
 152         DRM_DEBUG("\n");
 153
 154         mutex_lock(&drm_global_mutex);
 155         minor = idr_find(&drm_minors_idr, minor_id);
 156         if (!minor)
 157                 goto out;
 158
 159         if (!(dev = minor->dev))
 160                 goto out;
 161
 162         if (drm_device_is_unplugged(dev))
 163                 goto out;
 164
 165         new_fops = fops_get(dev->driver->fops);
 166         if (!new_fops)
 167                 goto out;
 168
 169         replace_fops(filp, new_fops);
 170         if (filp->f_op->open)
 171                 err = filp->f_op->open(inode, filp);
 172 out:
 173         mutex_unlock(&drm_global_mutex);
 174         return err;
 175 }
 176
 177 /**
 178  * Check whether DRI will run on this CPU.
 179  *
 180  * \return non-zero if the DRI will run on this CPU, or zero otherwise.
 181  */
 182 static int drm_cpu_valid(void)
 183 {
 184 #if defined(__i386__)
 185         if (boot_cpu_data.x86 == 3)
 186                 return 0;       /* No cmpxchg on a 386 */
 187 #endif
 188 #if defined(__sparc__) && !defined(__sparc_v9__)
 189         return 0;               /* No cmpxchg before v9 sparc. */
 190 #endif
 191         return 1;
 192 }
 193
 194 /**
 195  * Called whenever a process opens /dev/drm.
 196  *
 197  * \param inode device inode.
 198  * \param filp file pointer.
 199  * \param dev device.
 200  * \return zero on success or a negative number on failure.
 201  *
 202  * Creates and initializes a drm_file structure for the file private data in \p
 203  * filp and add it into the double linked list in \p dev.
 204  */
 205 static int drm_open_helper(struct inode *inode, struct file *filp,
 206                            struct drm_device * dev)
 207 {
 208         int minor_id = iminor(inode);
 209         struct drm_file *priv;
 210         int ret;
 211
 212         if (filp->f_flags & O_EXCL)
 213                 return -EBUSY;  /* No exclusive opens */
 214         if (!drm_cpu_valid())
 215                 return -EINVAL;
 216         if (dev->switch_power_state != DRM_SWITCH_POWER_ON && dev->switch_power_state != DRM_SWITCH_POWER_DYNAMIC_OFF)
 217                 return -EINVAL;
 218
 219         DRM_DEBUG("pid = %d, minor = %d\n", task_pid_nr(current), minor_id);
 220
 221         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 222         if (!priv)
 223                 return -ENOMEM;
 224
 225         filp->private_data = priv;
 226         priv->filp = filp;
 227         priv->uid = current_euid();
 228         priv->pid = get_pid(task_pid(current));
 229         priv->minor = idr_find(&drm_minors_idr, minor_id);
 230         if (!priv->minor) {
 231                 ret = -ENODEV;
 232                 goto out_put_pid;
 233         }
 234
 235         /* for compatibility root is always authenticated */
 236         priv->always_authenticated = capable(CAP_SYS_ADMIN);
 237         priv->authenticated = priv->always_authenticated;
 238         priv->lock_count = 0;
 239
 240         INIT_LIST_HEAD(&priv->lhead);
 241         INIT_LIST_HEAD(&priv->fbs);
 242         mutex_init(&priv->fbs_lock);
 243         INIT_LIST_HEAD(&priv->event_list);
 244         init_waitqueue_head(&priv->event_wait);
 245         priv->event_space = 4096; /* set aside 4k for event buffer */
 246
 247         if (dev->driver->driver_features & DRIVER_GEM)
 248                 drm_gem_open(dev, priv);
 249
 250         if (drm_core_check_feature(dev, DRIVER_PRIME))
 251                 drm_prime_init_file_private(&priv->prime);
 252
 253         if (dev->driver->open) {
 254                 ret = dev->driver->open(dev, priv);
 255                 if (ret < 0)
 256                         goto out_prime_destroy;
 257         }
 258
 259         /* if there is no current master make this fd it, but do not create
 260          * any master object for render clients */
 261         mutex_lock(&dev->struct_mutex);
 262         if (!priv->minor->master && !drm_is_render_client(priv)) {
 263                 /* create a new master */
 264                 priv->minor->master = drm_master_create(priv->minor);
 265                 if (!priv->minor->master) {
 266                         mutex_unlock(&dev->struct_mutex);
 267                         ret = -ENOMEM;
 268                         goto out_close;
 269                 }
 270
 271                 priv->is_master = 1;
 272                 /* take another reference for the copy in the local file priv */
 273                 priv->master = drm_master_get(priv->minor->master);
 274
 275                 priv->authenticated = 1;
 276
 277                 mutex_unlock(&dev->struct_mutex);
 278                 if (dev->driver->master_create) {
 279                         ret = dev->driver->master_create(dev, priv->master);
 280                         if (ret) {
 281                                 mutex_lock(&dev->struct_mutex);
 282                                 /* drop both references if this fails */
 283                                 drm_master_put(&priv->minor->master);
 284                                 drm_master_put(&priv->master);
 285                                 mutex_unlock(&dev->struct_mutex);
 286                                 goto out_close;
 287                         }
 288                 }
 289                 mutex_lock(&dev->struct_mutex);
 290                 if (dev->driver->master_set) {
 291                         ret = dev->driver->master_set(dev, priv, true);
 292                         if (ret) {
 293                                 /* drop both references if this fails */
 294                                 drm_master_put(&priv->minor->master);
 295                                 drm_master_put(&priv->master);
 296                                 mutex_unlock(&dev->struct_mutex);
 297                                 goto out_close;
 298                         }
 299                 }
 300         } else if (!drm_is_render_client(priv)) {
 301                 /* get a reference to the master */
 302                 priv->master = drm_master_get(priv->minor->master);
 303         }
 304         mutex_unlock(&dev->struct_mutex);
 305
 306         mutex_lock(&dev->struct_mutex);
 307         list_add(&priv->lhead, &dev->filelist);
 308         mutex_unlock(&dev->struct_mutex);
 309
 310 #ifdef __alpha__
 311         /*
 312          * Default the hose
 313          */
 314         if (!dev->hose) {
 315                 struct pci_dev *pci_dev;
 316                 pci_dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
 317                 if (pci_dev) {
 318                         dev->hose = pci_dev->sysdata;
 319                         pci_dev_put(pci_dev);
 320                 }
 321                 if (!dev->hose) {
 322                         struct pci_bus *b = list_entry(pci_root_buses.next,
 323                                 struct pci_bus, node);
 324                         if (b)
 325                                 dev->hose = b->sysdata;
 326                 }
 327         }
 328 #endif
 329
 330         return 0;
 331
 332 out_close:
 333         if (dev->driver->postclose)
 334                 dev->driver->postclose(dev, priv);
 335 out_prime_destroy:
 336         if (drm_core_check_feature(dev, DRIVER_PRIME))
 337                 drm_prime_destroy_file_private(&priv->prime);
 338         if (dev->driver->driver_features & DRIVER_GEM)
 339                 drm_gem_release(dev, priv);
 340 out_put_pid:
 341         put_pid(priv->pid);
 342         kfree(priv);
 343         filp->private_data = NULL;
 344         return ret;
 345 }
 346
 347 static void drm_master_release(struct drm_device *dev, struct file *filp)
 348 {
 349         struct drm_file *file_priv = filp->private_data;
 350
 351         if (drm_i_have_hw_lock(dev, file_priv)) {
 352                 DRM_DEBUG("File %p released, freeing lock for context %d\n",
 353                           filp, _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
 354                 drm_lock_free(&file_priv->master->lock,
 355                               _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
 356         }
 357 }
 358
 359 static void drm_events_release(struct drm_file *file_priv)
 360 {
 361         struct drm_device *dev = file_priv->minor->dev;
 362         struct drm_pending_event *e, *et;
 363         struct drm_pending_vblank_event *v, *vt;
 364         unsigned long flags;
 365
 366         spin_lock_irqsave(&dev->event_lock, flags);
 367
 368         /* Remove pending flips */
 369         list_for_each_entry_safe(v, vt, &dev->vblank_event_list, base.link)
 370                 if (v->base.file_priv == file_priv) {
 371                         list_del(&v->base.link);
 372                         drm_vblank_put(dev, v->pipe);
 373                         v->base.destroy(&v->base);
 374                 }
 375
 376         /* Remove unconsumed events */
 377         list_for_each_entry_safe(e, et, &file_priv->event_list, link) {
 378                 list_del(&e->link);
 379                 e->destroy(e);
 380         }
 381
 382         spin_unlock_irqrestore(&dev->event_lock, flags);
 383 }
 384
 385 /**
 386  * drm_legacy_dev_reinit
 387  *
 388  * Reinitializes a legacy/ums drm device in it's lastclose function.
 389  */
 390 static void drm_legacy_dev_reinit(struct drm_device *dev)
 391 {
 392         if (drm_core_check_feature(dev, DRIVER_MODESET))
 393                 return;
 394
 395         dev->sigdata.lock = NULL;
 396
 397         dev->context_flag = 0;
 398         dev->last_context = 0;
 399         dev->if_version = 0;
 400 }
 401
 402 /**
 403  * Take down the DRM device.
 404  *
 405  * \param dev DRM device structure.
 406  *
 407  * Frees every resource in \p dev.
 408  *
 409  * \sa drm_device
 410  */
 411 int drm_lastclose(struct drm_device * dev)
 412 {
 413         struct drm_vma_entry *vma, *vma_temp;
 414
 415         DRM_DEBUG("\n");
 416
 417         if (dev->driver->lastclose)
 418                 dev->driver->lastclose(dev);
 419         DRM_DEBUG("driver lastclose completed\n");
 420
 421         if (dev->irq_enabled && !drm_core_check_feature(dev, DRIVER_MODESET))
 422                 drm_irq_uninstall(dev);
 423
 424         mutex_lock(&dev->struct_mutex);
 425
 426         drm_agp_clear(dev);
 427
 428         drm_legacy_sg_cleanup(dev);
 429
 430         /* Clear vma list (only built for debugging) */
 431         list_for_each_entry_safe(vma, vma_temp, &dev->vmalist, head) {
 432                 list_del(&vma->head);
 433                 kfree(vma);
 434         }
 435
 436         drm_legacy_dma_takedown(dev);
 437
 438         dev->dev_mapping = NULL;
 439         mutex_unlock(&dev->struct_mutex);
 440
 441         drm_legacy_dev_reinit(dev);
 442
 443         DRM_DEBUG("lastclose completed\n");
 444         return 0;
 445 }
 446
 447 /**
 448  * Release file.
 449  *
 450  * \param inode device inode
 451  * \param file_priv DRM file private.
 452  * \return zero on success or a negative number on failure.
 453  *
 454  * If the hardware lock is held then free it, and take it again for the kernel
 455  * context since it's necessary to reclaim buffers. Unlink the file private
 456  * data from its list and free it. Decreases the open count and if it reaches
 457  * zero calls drm_lastclose().
 458  */
 459 int drm_release(struct inode *inode, struct file *filp)
 460 {
 461         struct drm_file *file_priv = filp->private_data;
 462         struct drm_device *dev = file_priv->minor->dev;
 463         int retcode = 0;
 464
 465         mutex_lock(&drm_global_mutex);
 466
 467         DRM_DEBUG("open_count = %d\n", dev->open_count);
 468
 469         if (dev->driver->preclose)
 470                 dev->driver->preclose(dev, file_priv);
 471
 472         /* ========================================================
 473          * Begin inline drm_release
 474          */
 475
 476         DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
 477                   task_pid_nr(current),
 478                   (long)old_encode_dev(file_priv->minor->device),
 479                   dev->open_count);
 480
 481         /* Release any auth tokens that might point to this file_priv,
 482            (do that under the drm_global_mutex) */
 483         if (file_priv->magic)
 484                 (void) drm_remove_magic(file_priv->master, file_priv->magic);
 485
 486         /* if the master has gone away we can't do anything with the lock */
 487         if (file_priv->minor->master)
 488                 drm_master_release(dev, filp);
 489
 490         if (drm_core_check_feature(dev, DRIVER_HAVE_DMA))
 491                 drm_core_reclaim_buffers(dev, file_priv);
 492
 493         drm_events_release(file_priv);
 494
 495         if (dev->driver->driver_features & DRIVER_MODESET)
 496                 drm_fb_release(file_priv);
 497
 498         if (dev->driver->driver_features & DRIVER_GEM)
 499                 drm_gem_release(dev, file_priv);
 500
 501         mutex_lock(&dev->ctxlist_mutex);
 502         if (!list_empty(&dev->ctxlist)) {
 503                 struct drm_ctx_list *pos, *n;
 504
 505                 list_for_each_entry_safe(pos, n, &dev->ctxlist, head) {
 506                         if (pos->tag == file_priv &&
 507                             pos->handle != DRM_KERNEL_CONTEXT) {
 508                                 if (dev->driver->context_dtor)
 509                                         dev->driver->context_dtor(dev,
 510                                                                   pos->handle);
 511
 512                                 drm_ctxbitmap_free(dev, pos->handle);
 513
 514                                 list_del(&pos->head);
 515                                 kfree(pos);
 516                         }
 517                 }
 518         }
 519         mutex_unlock(&dev->ctxlist_mutex);
 520
 521         mutex_lock(&dev->struct_mutex);
 522
 523         if (file_priv->is_master) {
 524                 struct drm_master *master = file_priv->master;
 525                 struct drm_file *temp;
 526                 list_for_each_entry(temp, &dev->filelist, lhead) {
 527                         if ((temp->master == file_priv->master) &&
 528                             (temp != file_priv))
 529                                 temp->authenticated = temp->always_authenticated;
 530                 }
 531
 532                 /**
 533                  * Since the master is disappearing, so is the
 534                  * possibility to lock.
 535                  */
 536
 537                 if (master->lock.hw_lock) {
 538                         if (dev->sigdata.lock == master->lock.hw_lock)
 539                                 dev->sigdata.lock = NULL;
 540                         master->lock.hw_lock = NULL;
 541                         master->lock.file_priv = NULL;
 542                         wake_up_interruptible_all(&master->lock.lock_queue);
 543                 }
 544
 545                 if (file_priv->minor->master == file_priv->master) {
 546                         /* drop the reference held my the minor */
 547                         if (dev->driver->master_drop)
 548                                 dev->driver->master_drop(dev, file_priv, true);
 549                         drm_master_put(&file_priv->minor->master);
 550                 }
 551         }
 552
 553         BUG_ON(dev->dev_mapping == NULL);
 554         iput(container_of(dev->dev_mapping, struct inode, i_data));
 555
 556         /* drop the reference held my the file priv */
 557         if (file_priv->master)
 558                 drm_master_put(&file_priv->master);
 559         file_priv->is_master = 0;
 560         list_del(&file_priv->lhead);
 561         mutex_unlock(&dev->struct_mutex);
 562
 563         if (dev->driver->postclose)
 564                 dev->driver->postclose(dev, file_priv);
 565
 566
 567         if (drm_core_check_feature(dev, DRIVER_PRIME))
 568                 drm_prime_destroy_file_private(&file_priv->prime);
 569
 570         put_pid(file_priv->pid);
 571         kfree(file_priv);
 572
 573         /* ========================================================
 574          * End inline drm_release
 575          */
 576
 577         if (!--dev->open_count) {
 578                 retcode = drm_lastclose(dev);
 579                 if (drm_device_is_unplugged(dev))
 580                         drm_put_dev(dev);
 581         }
 582         mutex_unlock(&drm_global_mutex);
 583
 584         return retcode;
 585 }
 586 EXPORT_SYMBOL(drm_release);
 587
 588 static bool
 589 drm_dequeue_event(struct drm_file *file_priv,
 590                   size_t total, size_t max, struct drm_pending_event **out)
 591 {
 592         struct drm_device *dev = file_priv->minor->dev;
 593         struct drm_pending_event *e;
 594         unsigned long flags;
 595         bool ret = false;
 596
 597         spin_lock_irqsave(&dev->event_lock, flags);
 598
 599         *out = NULL;
 600         if (list_empty(&file_priv->event_list))
 601                 goto out;
 602         e = list_first_entry(&file_priv->event_list,
 603                              struct drm_pending_event, link);
 604         if (e->event->length + total > max)
 605                 goto out;
 606
 607         file_priv->event_space += e->event->length;
 608         list_del(&e->link);
 609         *out = e;
 610         ret = true;
 611
 612 out:
 613         spin_unlock_irqrestore(&dev->event_lock, flags);
 614         return ret;
 615 }
 616
 617 ssize_t drm_read(struct file *filp, char __user *buffer,
 618                  size_t count, loff_t *offset)
 619 {
 620         struct drm_file *file_priv = filp->private_data;
 621         struct drm_pending_event *e;
 622         size_t total;
 623         ssize_t ret;
 624
 625         ret = wait_event_interruptible(file_priv->event_wait,
 626                                        !list_empty(&file_priv->event_list));
 627         if (ret < 0)
 628                 return ret;
 629
 630         total = 0;
 631         while (drm_dequeue_event(file_priv, total, count, &e)) {
 632                 if (copy_to_user(buffer + total,
 633                                  e->event, e->event->length)) {
 634                         total = -EFAULT;
 635                         break;
 636                 }
 637
 638                 total += e->event->length;
 639                 e->destroy(e);
 640         }
 641
 642         return total;
 643 }
 644 EXPORT_SYMBOL(drm_read);
 645
 646 unsigned int drm_poll(struct file *filp, struct poll_table_struct *wait)
 647 {
 648         struct drm_file *file_priv = filp->private_data;
 649         unsigned int mask = 0;
 650
 651         poll_wait(filp, &file_priv->event_wait, wait);
 652
 653         if (!list_empty(&file_priv->event_list))
 654                 mask |= POLLIN | POLLRDNORM;
 655
 656         return mask;
 657 }
 658 EXPORT_SYMBOL(drm_poll);