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 *old_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         old_fops = filp->f_op;
 166         filp->f_op = fops_get(dev->driver->fops);
 167         if (filp->f_op == NULL) {
 168                 filp->f_op = old_fops;
 169                 goto out;
 170         }
 171         if (filp->f_op->open && (err = filp->f_op->open(inode, filp))) {
 172                 fops_put(filp->f_op);
 173                 filp->f_op = fops_get(old_fops);
 174         }
 175         fops_put(old_fops);
 176
 177 out:
 178         mutex_unlock(&drm_global_mutex);
 179         return err;
 180 }
 181
 182 /**
 183  * Check whether DRI will run on this CPU.
 184  *
 185  * \return non-zero if the DRI will run on this CPU, or zero otherwise.
 186  */
 187 static int drm_cpu_valid(void)
 188 {
 189 #if defined(__i386__)
 190         if (boot_cpu_data.x86 == 3)
 191                 return 0;       /* No cmpxchg on a 386 */
 192 #endif
 193 #if defined(__sparc__) && !defined(__sparc_v9__)
 194         return 0;               /* No cmpxchg before v9 sparc. */
 195 #endif
 196         return 1;
 197 }
 198
 199 /**
 200  * Called whenever a process opens /dev/drm.
 201  *
 202  * \param inode device inode.
 203  * \param filp file pointer.
 204  * \param dev device.
 205  * \return zero on success or a negative number on failure.
 206  *
 207  * Creates and initializes a drm_file structure for the file private data in \p
 208  * filp and add it into the double linked list in \p dev.
 209  */
 210 static int drm_open_helper(struct inode *inode, struct file *filp,
 211                            struct drm_device * dev)
 212 {
 213         int minor_id = iminor(inode);
 214         struct drm_file *priv;
 215         int ret;
 216
 217         if (filp->f_flags & O_EXCL)
 218                 return -EBUSY;  /* No exclusive opens */
 219         if (!drm_cpu_valid())
 220                 return -EINVAL;
 221         if (dev->switch_power_state != DRM_SWITCH_POWER_ON && dev->switch_power_state != DRM_SWITCH_POWER_DYNAMIC_OFF)
 222                 return -EINVAL;
 223
 224         DRM_DEBUG("pid = %d, minor = %d\n", task_pid_nr(current), minor_id);
 225
 226         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 227         if (!priv)
 228                 return -ENOMEM;
 229
 230         filp->private_data = priv;
 231         priv->filp = filp;
 232         priv->uid = current_euid();
 233         priv->pid = get_pid(task_pid(current));
 234         priv->minor = idr_find(&drm_minors_idr, minor_id);
 235         if (!priv->minor) {
 236                 ret = -ENODEV;
 237                 goto out_put_pid;
 238         }
 239
 240         priv->ioctl_count = 0;
 241         /* for compatibility root is always authenticated */
 242         priv->authenticated = capable(CAP_SYS_ADMIN);
 243         priv->lock_count = 0;
 244
 245         INIT_LIST_HEAD(&priv->lhead);
 246         INIT_LIST_HEAD(&priv->fbs);
 247         mutex_init(&priv->fbs_lock);
 248         INIT_LIST_HEAD(&priv->event_list);
 249         init_waitqueue_head(&priv->event_wait);
 250         priv->event_space = 4096; /* set aside 4k for event buffer */
 251
 252         if (dev->driver->driver_features & DRIVER_GEM)
 253                 drm_gem_open(dev, priv);
 254
 255         if (drm_core_check_feature(dev, DRIVER_PRIME))
 256                 drm_prime_init_file_private(&priv->prime);
 257
 258         if (dev->driver->open) {
 259                 ret = dev->driver->open(dev, priv);
 260                 if (ret < 0)
 261                         goto out_prime_destroy;
 262         }
 263
 264         /* if there is no current master make this fd it, but do not create
 265          * any master object for render clients */
 266         mutex_lock(&dev->struct_mutex);
 267         if (!priv->minor->master && !drm_is_render_client(priv)) {
 268                 /* create a new master */
 269                 priv->minor->master = drm_master_create(priv->minor);
 270                 if (!priv->minor->master) {
 271                         mutex_unlock(&dev->struct_mutex);
 272                         ret = -ENOMEM;
 273                         goto out_close;
 274                 }
 275
 276                 priv->is_master = 1;
 277                 /* take another reference for the copy in the local file priv */
 278                 priv->master = drm_master_get(priv->minor->master);
 279
 280                 priv->authenticated = 1;
 281
 282                 mutex_unlock(&dev->struct_mutex);
 283                 if (dev->driver->master_create) {
 284                         ret = dev->driver->master_create(dev, priv->master);
 285                         if (ret) {
 286                                 mutex_lock(&dev->struct_mutex);
 287                                 /* drop both references if this fails */
 288                                 drm_master_put(&priv->minor->master);
 289                                 drm_master_put(&priv->master);
 290                                 mutex_unlock(&dev->struct_mutex);
 291                                 goto out_close;
 292                         }
 293                 }
 294                 mutex_lock(&dev->struct_mutex);
 295                 if (dev->driver->master_set) {
 296                         ret = dev->driver->master_set(dev, priv, true);
 297                         if (ret) {
 298                                 /* drop both references if this fails */
 299                                 drm_master_put(&priv->minor->master);
 300                                 drm_master_put(&priv->master);
 301                                 mutex_unlock(&dev->struct_mutex);
 302                                 goto out_close;
 303                         }
 304                 }
 305         } else if (!drm_is_render_client(priv)) {
 306                 /* get a reference to the master */
 307                 priv->master = drm_master_get(priv->minor->master);
 308         }
 309         mutex_unlock(&dev->struct_mutex);
 310
 311         mutex_lock(&dev->struct_mutex);
 312         list_add(&priv->lhead, &dev->filelist);
 313         mutex_unlock(&dev->struct_mutex);
 314
 315 #ifdef __alpha__
 316         /*
 317          * Default the hose
 318          */
 319         if (!dev->hose) {
 320                 struct pci_dev *pci_dev;
 321                 pci_dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
 322                 if (pci_dev) {
 323                         dev->hose = pci_dev->sysdata;
 324                         pci_dev_put(pci_dev);
 325                 }
 326                 if (!dev->hose) {
 327                         struct pci_bus *b = pci_bus_b(pci_root_buses.next);
 328                         if (b)
 329                                 dev->hose = b->sysdata;
 330                 }
 331         }
 332 #endif
 333
 334         return 0;
 335
 336 out_close:
 337         if (dev->driver->postclose)
 338                 dev->driver->postclose(dev, priv);
 339 out_prime_destroy:
 340         if (drm_core_check_feature(dev, DRIVER_PRIME))
 341                 drm_prime_destroy_file_private(&priv->prime);
 342         if (dev->driver->driver_features & DRIVER_GEM)
 343                 drm_gem_release(dev, priv);
 344 out_put_pid:
 345         put_pid(priv->pid);
 346         kfree(priv);
 347         filp->private_data = NULL;
 348         return ret;
 349 }
 350
 351 static void drm_master_release(struct drm_device *dev, struct file *filp)
 352 {
 353         struct drm_file *file_priv = filp->private_data;
 354
 355         if (drm_i_have_hw_lock(dev, file_priv)) {
 356                 DRM_DEBUG("File %p released, freeing lock for context %d\n",
 357                           filp, _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
 358                 drm_lock_free(&file_priv->master->lock,
 359                               _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
 360         }
 361 }
 362
 363 static void drm_events_release(struct drm_file *file_priv)
 364 {
 365         struct drm_device *dev = file_priv->minor->dev;
 366         struct drm_pending_event *e, *et;
 367         struct drm_pending_vblank_event *v, *vt;
 368         unsigned long flags;
 369
 370         spin_lock_irqsave(&dev->event_lock, flags);
 371
 372         /* Remove pending flips */
 373         list_for_each_entry_safe(v, vt, &dev->vblank_event_list, base.link)
 374                 if (v->base.file_priv == file_priv) {
 375                         list_del(&v->base.link);
 376                         drm_vblank_put(dev, v->pipe);
 377                         v->base.destroy(&v->base);
 378                 }
 379
 380         /* Remove unconsumed events */
 381         list_for_each_entry_safe(e, et, &file_priv->event_list, link)
 382                 e->destroy(e);
 383
 384         spin_unlock_irqrestore(&dev->event_lock, flags);
 385 }
 386
 387 /**
 388  * drm_legacy_dev_reinit
 389  *
 390  * Reinitializes a legacy/ums drm device in it's lastclose function.
 391  */
 392 static void drm_legacy_dev_reinit(struct drm_device *dev)
 393 {
 394         if (drm_core_check_feature(dev, DRIVER_MODESET))
 395                 return;
 396
 397         atomic_set(&dev->ioctl_count, 0);
 398         atomic_set(&dev->vma_count, 0);
 399
 400         dev->sigdata.lock = NULL;
 401
 402         dev->context_flag = 0;
 403         dev->last_context = 0;
 404         dev->if_version = 0;
 405 }
 406
 407 /**
 408  * Take down the DRM device.
 409  *
 410  * \param dev DRM device structure.
 411  *
 412  * Frees every resource in \p dev.
 413  *
 414  * \sa drm_device
 415  */
 416 int drm_lastclose(struct drm_device * dev)
 417 {
 418         struct drm_vma_entry *vma, *vma_temp;
 419
 420         DRM_DEBUG("\n");
 421
 422         if (dev->driver->lastclose)
 423                 dev->driver->lastclose(dev);
 424         DRM_DEBUG("driver lastclose completed\n");
 425
 426         if (dev->irq_enabled && !drm_core_check_feature(dev, DRIVER_MODESET))
 427                 drm_irq_uninstall(dev);
 428
 429         mutex_lock(&dev->struct_mutex);
 430
 431         drm_agp_clear(dev);
 432
 433         drm_legacy_sg_cleanup(dev);
 434
 435         /* Clear vma list (only built for debugging) */
 436         list_for_each_entry_safe(vma, vma_temp, &dev->vmalist, head) {
 437                 list_del(&vma->head);
 438                 kfree(vma);
 439         }
 440
 441         drm_legacy_dma_takedown(dev);
 442
 443         dev->dev_mapping = NULL;
 444         mutex_unlock(&dev->struct_mutex);
 445
 446         drm_legacy_dev_reinit(dev);
 447
 448         DRM_DEBUG("lastclose completed\n");
 449         return 0;
 450 }
 451
 452 /**
 453  * Release file.
 454  *
 455  * \param inode device inode
 456  * \param file_priv DRM file private.
 457  * \return zero on success or a negative number on failure.
 458  *
 459  * If the hardware lock is held then free it, and take it again for the kernel
 460  * context since it's necessary to reclaim buffers. Unlink the file private
 461  * data from its list and free it. Decreases the open count and if it reaches
 462  * zero calls drm_lastclose().
 463  */
 464 int drm_release(struct inode *inode, struct file *filp)
 465 {
 466         struct drm_file *file_priv = filp->private_data;
 467         struct drm_device *dev = file_priv->minor->dev;
 468         int retcode = 0;
 469
 470         mutex_lock(&drm_global_mutex);
 471
 472         DRM_DEBUG("open_count = %d\n", dev->open_count);
 473
 474         if (dev->driver->preclose)
 475                 dev->driver->preclose(dev, file_priv);
 476
 477         /* ========================================================
 478          * Begin inline drm_release
 479          */
 480
 481         DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
 482                   task_pid_nr(current),
 483                   (long)old_encode_dev(file_priv->minor->device),
 484                   dev->open_count);
 485
 486         /* Release any auth tokens that might point to this file_priv,
 487            (do that under the drm_global_mutex) */
 488         if (file_priv->magic)
 489                 (void) drm_remove_magic(file_priv->master, file_priv->magic);
 490
 491         /* if the master has gone away we can't do anything with the lock */
 492         if (file_priv->minor->master)
 493                 drm_master_release(dev, filp);
 494
 495         if (drm_core_check_feature(dev, DRIVER_HAVE_DMA))
 496                 drm_core_reclaim_buffers(dev, file_priv);
 497
 498         drm_events_release(file_priv);
 499
 500         if (dev->driver->driver_features & DRIVER_MODESET)
 501                 drm_fb_release(file_priv);
 502
 503         if (dev->driver->driver_features & DRIVER_GEM)
 504                 drm_gem_release(dev, file_priv);
 505
 506         mutex_lock(&dev->ctxlist_mutex);
 507         if (!list_empty(&dev->ctxlist)) {
 508                 struct drm_ctx_list *pos, *n;
 509
 510                 list_for_each_entry_safe(pos, n, &dev->ctxlist, head) {
 511                         if (pos->tag == file_priv &&
 512                             pos->handle != DRM_KERNEL_CONTEXT) {
 513                                 if (dev->driver->context_dtor)
 514                                         dev->driver->context_dtor(dev,
 515                                                                   pos->handle);
 516
 517                                 drm_ctxbitmap_free(dev, pos->handle);
 518
 519                                 list_del(&pos->head);
 520                                 kfree(pos);
 521                         }
 522                 }
 523         }
 524         mutex_unlock(&dev->ctxlist_mutex);
 525
 526         mutex_lock(&dev->struct_mutex);
 527
 528         if (file_priv->is_master) {
 529                 struct drm_master *master = file_priv->master;
 530                 struct drm_file *temp;
 531                 list_for_each_entry(temp, &dev->filelist, lhead) {
 532                         if ((temp->master == file_priv->master) &&
 533                             (temp != file_priv))
 534                                 temp->authenticated = 0;
 535                 }
 536
 537                 /**
 538                  * Since the master is disappearing, so is the
 539                  * possibility to lock.
 540                  */
 541
 542                 if (master->lock.hw_lock) {
 543                         if (dev->sigdata.lock == master->lock.hw_lock)
 544                                 dev->sigdata.lock = NULL;
 545                         master->lock.hw_lock = NULL;
 546                         master->lock.file_priv = NULL;
 547                         wake_up_interruptible_all(&master->lock.lock_queue);
 548                 }
 549
 550                 if (file_priv->minor->master == file_priv->master) {
 551                         /* drop the reference held my the minor */
 552                         if (dev->driver->master_drop)
 553                                 dev->driver->master_drop(dev, file_priv, true);
 554                         drm_master_put(&file_priv->minor->master);
 555                 }
 556         }
 557
 558         BUG_ON(dev->dev_mapping == NULL);
 559         iput(container_of(dev->dev_mapping, struct inode, i_data));
 560
 561         /* drop the reference held my the file priv */
 562         if (file_priv->master)
 563                 drm_master_put(&file_priv->master);
 564         file_priv->is_master = 0;
 565         list_del(&file_priv->lhead);
 566         mutex_unlock(&dev->struct_mutex);
 567
 568         if (dev->driver->postclose)
 569                 dev->driver->postclose(dev, file_priv);
 570
 571
 572         if (drm_core_check_feature(dev, DRIVER_PRIME))
 573                 drm_prime_destroy_file_private(&file_priv->prime);
 574
 575         put_pid(file_priv->pid);
 576         kfree(file_priv);
 577
 578         /* ========================================================
 579          * End inline drm_release
 580          */
 581
 582         if (!--dev->open_count) {
 583                 if (atomic_read(&dev->ioctl_count)) {
 584                         DRM_ERROR("Device busy: %d\n",
 585                                   atomic_read(&dev->ioctl_count));
 586                         retcode = -EBUSY;
 587                 } else
 588                         retcode = drm_lastclose(dev);
 589                 if (drm_device_is_unplugged(dev))
 590                         drm_put_dev(dev);
 591         }
 592         mutex_unlock(&drm_global_mutex);
 593
 594         return retcode;
 595 }
 596 EXPORT_SYMBOL(drm_release);
 597
 598 static bool
 599 drm_dequeue_event(struct drm_file *file_priv,
 600                   size_t total, size_t max, struct drm_pending_event **out)
 601 {
 602         struct drm_device *dev = file_priv->minor->dev;
 603         struct drm_pending_event *e;
 604         unsigned long flags;
 605         bool ret = false;
 606
 607         spin_lock_irqsave(&dev->event_lock, flags);
 608
 609         *out = NULL;
 610         if (list_empty(&file_priv->event_list))
 611                 goto out;
 612         e = list_first_entry(&file_priv->event_list,
 613                              struct drm_pending_event, link);
 614         if (e->event->length + total > max)
 615                 goto out;
 616
 617         file_priv->event_space += e->event->length;
 618         list_del(&e->link);
 619         *out = e;
 620         ret = true;
 621
 622 out:
 623         spin_unlock_irqrestore(&dev->event_lock, flags);
 624         return ret;
 625 }
 626
 627 ssize_t drm_read(struct file *filp, char __user *buffer,
 628                  size_t count, loff_t *offset)
 629 {
 630         struct drm_file *file_priv = filp->private_data;
 631         struct drm_pending_event *e;
 632         size_t total;
 633         ssize_t ret;
 634
 635         ret = wait_event_interruptible(file_priv->event_wait,
 636                                        !list_empty(&file_priv->event_list));
 637         if (ret < 0)
 638                 return ret;
 639
 640         total = 0;
 641         while (drm_dequeue_event(file_priv, total, count, &e)) {
 642                 if (copy_to_user(buffer + total,
 643                                  e->event, e->event->length)) {
 644                         total = -EFAULT;
 645                         break;
 646                 }
 647
 648                 total += e->event->length;
 649                 e->destroy(e);
 650         }
 651
 652         return total;
 653 }
 654 EXPORT_SYMBOL(drm_read);
 655
 656 unsigned int drm_poll(struct file *filp, struct poll_table_struct *wait)
 657 {
 658         struct drm_file *file_priv = filp->private_data;
 659         unsigned int mask = 0;
 660
 661         poll_wait(filp, &file_priv->event_wait, wait);
 662
 663         if (!list_empty(&file_priv->event_list))
 664                 mask |= POLLIN | POLLRDNORM;
 665
 666         return mask;
 667 }
 668 EXPORT_SYMBOL(drm_poll);