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             !drm_is_control_client(priv)) {
 246                 /* create a new master */
 247                 priv->minor->master = drm_master_create(priv->minor);
 248                 if (!priv->minor->master) {
 249                         mutex_unlock(&dev->struct_mutex);
 250                         ret = -ENOMEM;
 251                         goto out_close;
 252                 }
 253
 254                 priv->is_master = 1;
 255                 /* take another reference for the copy in the local file priv */
 256                 priv->master = drm_master_get(priv->minor->master);
 257
 258                 priv->authenticated = 1;
 259
 260                 mutex_unlock(&dev->struct_mutex);
 261                 if (dev->driver->master_create) {
 262                         ret = dev->driver->master_create(dev, priv->master);
 263                         if (ret) {
 264                                 mutex_lock(&dev->struct_mutex);
 265                                 /* drop both references if this fails */
 266                                 drm_master_put(&priv->minor->master);
 267                                 drm_master_put(&priv->master);
 268                                 mutex_unlock(&dev->struct_mutex);
 269                                 goto out_close;
 270                         }
 271                 }
 272                 mutex_lock(&dev->struct_mutex);
 273                 if (dev->driver->master_set) {
 274                         ret = dev->driver->master_set(dev, priv, true);
 275                         if (ret) {
 276                                 /* drop both references if this fails */
 277                                 drm_master_put(&priv->minor->master);
 278                                 drm_master_put(&priv->master);
 279                                 mutex_unlock(&dev->struct_mutex);
 280                                 goto out_close;
 281                         }
 282                 }
 283         } else if (!drm_is_render_client(priv) &&
 284                    !drm_is_control_client(priv)) {
 285                 /* get a reference to the master */
 286                 priv->master = drm_master_get(priv->minor->master);
 287         }
 288         mutex_unlock(&dev->struct_mutex);
 289
 290         mutex_lock(&dev->struct_mutex);
 291         list_add(&priv->lhead, &dev->filelist);
 292         mutex_unlock(&dev->struct_mutex);
 293
 294 #ifdef __alpha__
 295         /*
 296          * Default the hose
 297          */
 298         if (!dev->hose) {
 299                 struct pci_dev *pci_dev;
 300                 pci_dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
 301                 if (pci_dev) {
 302                         dev->hose = pci_dev->sysdata;
 303                         pci_dev_put(pci_dev);
 304                 }
 305                 if (!dev->hose) {
 306                         struct pci_bus *b = pci_bus_b(pci_root_buses.next);
 307                         if (b)
 308                                 dev->hose = b->sysdata;
 309                 }
 310         }
 311 #endif
 312
 313         return 0;
 314
 315 out_close:
 316         if (dev->driver->postclose)
 317                 dev->driver->postclose(dev, priv);
 318 out_prime_destroy:
 319         if (drm_core_check_feature(dev, DRIVER_PRIME))
 320                 drm_prime_destroy_file_private(&priv->prime);
 321         if (dev->driver->driver_features & DRIVER_GEM)
 322                 drm_gem_release(dev, priv);
 323         put_pid(priv->pid);
 324         kfree(priv);
 325         filp->private_data = NULL;
 326         return ret;
 327 }
 328
 329 static void drm_master_release(struct drm_device *dev, struct file *filp)
 330 {
 331         struct drm_file *file_priv = filp->private_data;
 332
 333         if (drm_i_have_hw_lock(dev, file_priv)) {
 334                 DRM_DEBUG("File %p released, freeing lock for context %d\n",
 335                           filp, _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
 336                 drm_lock_free(&file_priv->master->lock,
 337                               _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
 338         }
 339 }
 340
 341 static void drm_events_release(struct drm_file *file_priv)
 342 {
 343         struct drm_device *dev = file_priv->minor->dev;
 344         struct drm_pending_event *e, *et;
 345         struct drm_pending_vblank_event *v, *vt;
 346         unsigned long flags;
 347
 348         spin_lock_irqsave(&dev->event_lock, flags);
 349
 350         /* Remove pending flips */
 351         list_for_each_entry_safe(v, vt, &dev->vblank_event_list, base.link)
 352                 if (v->base.file_priv == file_priv) {
 353                         list_del(&v->base.link);
 354                         drm_vblank_put(dev, v->pipe);
 355                         v->base.destroy(&v->base);
 356                 }
 357
 358         /* Remove unconsumed events */
 359         list_for_each_entry_safe(e, et, &file_priv->event_list, link) {
 360                 list_del(&e->link);
 361                 e->destroy(e);
 362         }
 363
 364         spin_unlock_irqrestore(&dev->event_lock, flags);
 365 }
 366
 367 /**
 368  * drm_legacy_dev_reinit
 369  *
 370  * Reinitializes a legacy/ums drm device in it's lastclose function.
 371  */
 372 static void drm_legacy_dev_reinit(struct drm_device *dev)
 373 {
 374         if (drm_core_check_feature(dev, DRIVER_MODESET))
 375                 return;
 376
 377         dev->sigdata.lock = NULL;
 378
 379         dev->context_flag = 0;
 380         dev->last_context = 0;
 381         dev->if_version = 0;
 382 }
 383
 384 /**
 385  * Take down the DRM device.
 386  *
 387  * \param dev DRM device structure.
 388  *
 389  * Frees every resource in \p dev.
 390  *
 391  * \sa drm_device
 392  */
 393 int drm_lastclose(struct drm_device * dev)
 394 {
 395         struct drm_vma_entry *vma, *vma_temp;
 396
 397         DRM_DEBUG("\n");
 398
 399         if (dev->driver->lastclose)
 400                 dev->driver->lastclose(dev);
 401         DRM_DEBUG("driver lastclose completed\n");
 402
 403         if (dev->irq_enabled && !drm_core_check_feature(dev, DRIVER_MODESET))
 404                 drm_irq_uninstall(dev);
 405
 406         mutex_lock(&dev->struct_mutex);
 407
 408         drm_agp_clear(dev);
 409
 410         drm_legacy_sg_cleanup(dev);
 411
 412         /* Clear vma list (only built for debugging) */
 413         list_for_each_entry_safe(vma, vma_temp, &dev->vmalist, head) {
 414                 list_del(&vma->head);
 415                 kfree(vma);
 416         }
 417
 418         drm_legacy_dma_takedown(dev);
 419
 420         mutex_unlock(&dev->struct_mutex);
 421
 422         drm_legacy_dev_reinit(dev);
 423
 424         DRM_DEBUG("lastclose completed\n");
 425         return 0;
 426 }
 427
 428 /**
 429  * Release file.
 430  *
 431  * \param inode device inode
 432  * \param file_priv DRM file private.
 433  * \return zero on success or a negative number on failure.
 434  *
 435  * If the hardware lock is held then free it, and take it again for the kernel
 436  * context since it's necessary to reclaim buffers. Unlink the file private
 437  * data from its list and free it. Decreases the open count and if it reaches
 438  * zero calls drm_lastclose().
 439  */
 440 int drm_release(struct inode *inode, struct file *filp)
 441 {
 442         struct drm_file *file_priv = filp->private_data;
 443         struct drm_minor *minor = file_priv->minor;
 444         struct drm_device *dev = minor->dev;
 445         int retcode = 0;
 446
 447         mutex_lock(&drm_global_mutex);
 448
 449         DRM_DEBUG("open_count = %d\n", dev->open_count);
 450
 451         if (dev->driver->preclose)
 452                 dev->driver->preclose(dev, file_priv);
 453
 454         /* ========================================================
 455          * Begin inline drm_release
 456          */
 457
 458         DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
 459                   task_pid_nr(current),
 460                   (long)old_encode_dev(file_priv->minor->device),
 461                   dev->open_count);
 462
 463         /* Release any auth tokens that might point to this file_priv,
 464            (do that under the drm_global_mutex) */
 465         if (file_priv->magic)
 466                 (void) drm_remove_magic(file_priv->master, file_priv->magic);
 467
 468         /* if the master has gone away we can't do anything with the lock */
 469         if (file_priv->minor->master)
 470                 drm_master_release(dev, filp);
 471
 472         if (drm_core_check_feature(dev, DRIVER_HAVE_DMA))
 473                 drm_core_reclaim_buffers(dev, file_priv);
 474
 475         drm_events_release(file_priv);
 476
 477         if (dev->driver->driver_features & DRIVER_MODESET)
 478                 drm_fb_release(file_priv);
 479
 480         if (dev->driver->driver_features & DRIVER_GEM)
 481                 drm_gem_release(dev, file_priv);
 482
 483         mutex_lock(&dev->ctxlist_mutex);
 484         if (!list_empty(&dev->ctxlist)) {
 485                 struct drm_ctx_list *pos, *n;
 486
 487                 list_for_each_entry_safe(pos, n, &dev->ctxlist, head) {
 488                         if (pos->tag == file_priv &&
 489                             pos->handle != DRM_KERNEL_CONTEXT) {
 490                                 if (dev->driver->context_dtor)
 491                                         dev->driver->context_dtor(dev,
 492                                                                   pos->handle);
 493
 494                                 drm_ctxbitmap_free(dev, pos->handle);
 495
 496                                 list_del(&pos->head);
 497                                 kfree(pos);
 498                         }
 499                 }
 500         }
 501         mutex_unlock(&dev->ctxlist_mutex);
 502
 503         mutex_lock(&dev->struct_mutex);
 504
 505         if (file_priv->is_master) {
 506                 struct drm_master *master = file_priv->master;
 507                 struct drm_file *temp;
 508                 list_for_each_entry(temp, &dev->filelist, lhead) {
 509                         if ((temp->master == file_priv->master) &&
 510                             (temp != file_priv))
 511                                 temp->authenticated = temp->always_authenticated;
 512                 }
 513
 514                 /**
 515                  * Since the master is disappearing, so is the
 516                  * possibility to lock.
 517                  */
 518
 519                 if (master->lock.hw_lock) {
 520                         if (dev->sigdata.lock == master->lock.hw_lock)
 521                                 dev->sigdata.lock = NULL;
 522                         master->lock.hw_lock = NULL;
 523                         master->lock.file_priv = NULL;
 524                         wake_up_interruptible_all(&master->lock.lock_queue);
 525                 }
 526
 527                 if (file_priv->minor->master == file_priv->master) {
 528                         /* drop the reference held my the minor */
 529                         if (dev->driver->master_drop)
 530                                 dev->driver->master_drop(dev, file_priv, true);
 531                         drm_master_put(&file_priv->minor->master);
 532                 }
 533         }
 534
 535         /* drop the reference held my the file priv */
 536         if (file_priv->master)
 537                 drm_master_put(&file_priv->master);
 538         file_priv->is_master = 0;
 539         list_del(&file_priv->lhead);
 540         mutex_unlock(&dev->struct_mutex);
 541
 542         if (dev->driver->postclose)
 543                 dev->driver->postclose(dev, file_priv);
 544
 545
 546         if (drm_core_check_feature(dev, DRIVER_PRIME))
 547                 drm_prime_destroy_file_private(&file_priv->prime);
 548
 549         put_pid(file_priv->pid);
 550         kfree(file_priv);
 551
 552         /* ========================================================
 553          * End inline drm_release
 554          */
 555
 556         if (!--dev->open_count) {
 557                 retcode = drm_lastclose(dev);
 558                 if (drm_device_is_unplugged(dev))
 559                         drm_put_dev(dev);
 560         }
 561         mutex_unlock(&drm_global_mutex);
 562
 563         drm_minor_release(minor);
 564
 565         return retcode;
 566 }
 567 EXPORT_SYMBOL(drm_release);
 568
 569 static bool
 570 drm_dequeue_event(struct drm_file *file_priv,
 571                   size_t total, size_t max, struct drm_pending_event **out)
 572 {
 573         struct drm_device *dev = file_priv->minor->dev;
 574         struct drm_pending_event *e;
 575         unsigned long flags;
 576         bool ret = false;
 577
 578         spin_lock_irqsave(&dev->event_lock, flags);
 579
 580         *out = NULL;
 581         if (list_empty(&file_priv->event_list))
 582                 goto out;
 583         e = list_first_entry(&file_priv->event_list,
 584                              struct drm_pending_event, link);
 585         if (e->event->length + total > max)
 586                 goto out;
 587
 588         file_priv->event_space += e->event->length;
 589         list_del(&e->link);
 590         *out = e;
 591         ret = true;
 592
 593 out:
 594         spin_unlock_irqrestore(&dev->event_lock, flags);
 595         return ret;
 596 }
 597
 598 ssize_t drm_read(struct file *filp, char __user *buffer,
 599                  size_t count, loff_t *offset)
 600 {
 601         struct drm_file *file_priv = filp->private_data;
 602         struct drm_pending_event *e;
 603         size_t total;
 604         ssize_t ret;
 605
 606         ret = wait_event_interruptible(file_priv->event_wait,
 607                                        !list_empty(&file_priv->event_list));
 608         if (ret < 0)
 609                 return ret;
 610
 611         total = 0;
 612         while (drm_dequeue_event(file_priv, total, count, &e)) {
 613                 if (copy_to_user(buffer + total,
 614                                  e->event, e->event->length)) {
 615                         total = -EFAULT;
 616                         break;
 617                 }
 618
 619                 total += e->event->length;
 620                 e->destroy(e);
 621         }
 622
 623         return total;
 624 }
 625 EXPORT_SYMBOL(drm_read);
 626
 627 unsigned int drm_poll(struct file *filp, struct poll_table_struct *wait)
 628 {
 629         struct drm_file *file_priv = filp->private_data;
 630         unsigned int mask = 0;
 631
 632         poll_wait(filp, &file_priv->event_wait, wait);
 633
 634         if (!list_empty(&file_priv->event_list))
 635                 mask |= POLLIN | POLLRDNORM;
 636
 637         return mask;
 638 }
 639 EXPORT_SYMBOL(drm_poll);