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