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;
  83         struct drm_minor *minor;
  84         int retcode;
  85         int need_setup = 0;
  86         struct address_space *old_mapping;
  87         struct address_space *old_imapping;
  88
  89         minor = drm_minor_acquire(iminor(inode));
  90         if (IS_ERR(minor))
  91                 return PTR_ERR(minor);
  92
  93         dev = minor->dev;
  94         if (drm_device_is_unplugged(dev)) {
  95                 retcode = -ENODEV;
  96                 goto err_release;
  97         }
  98
  99         if (!dev->open_count++)
 100                 need_setup = 1;
 101         mutex_lock(&dev->struct_mutex);
 102         old_imapping = inode->i_mapping;
 103         old_mapping = dev->dev_mapping;
 104         if (old_mapping == NULL)
 105                 dev->dev_mapping = &inode->i_data;
 106         /* ihold ensures nobody can remove inode with our i_data */
 107         ihold(container_of(dev->dev_mapping, struct inode, i_data));
 108         inode->i_mapping = dev->dev_mapping;
 109         filp->f_mapping = dev->dev_mapping;
 110         mutex_unlock(&dev->struct_mutex);
 111
 112         retcode = drm_open_helper(inode, filp, dev);
 113         if (retcode)
 114                 goto err_undo;
 115         if (need_setup) {
 116                 retcode = drm_setup(dev);
 117                 if (retcode)
 118                         goto err_undo;
 119         }
 120         return 0;
 121
 122 err_undo:
 123         mutex_lock(&dev->struct_mutex);
 124         filp->f_mapping = old_imapping;
 125         inode->i_mapping = old_imapping;
 126         iput(container_of(dev->dev_mapping, struct inode, i_data));
 127         dev->dev_mapping = old_mapping;
 128         mutex_unlock(&dev->struct_mutex);
 129         dev->open_count--;
 130 err_release:
 131         drm_minor_release(minor);
 132         return retcode;
 133 }
 134 EXPORT_SYMBOL(drm_open);
 135
 136 /**
 137  * File \c open operation.
 138  *
 139  * \param inode device inode.
 140  * \param filp file pointer.
 141  *
 142  * Puts the dev->fops corresponding to the device minor number into
 143  * \p filp, call the \c open method, and restore the file operations.
 144  */
 145 int drm_stub_open(struct inode *inode, struct file *filp)
 146 {
 147         struct drm_device *dev;
 148         struct drm_minor *minor;
 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 = drm_minor_acquire(iminor(inode));
 156         if (IS_ERR(minor))
 157                 goto out_unlock;
 158
 159         dev = minor->dev;
 160         if (drm_device_is_unplugged(dev))
 161                 goto out_release;
 162
 163         new_fops = fops_get(dev->driver->fops);
 164         if (!new_fops)
 165                 goto out_release;
 166
 167         replace_fops(filp, new_fops);
 168         if (filp->f_op->open)
 169                 err = filp->f_op->open(inode, filp);
 170
 171 out_release:
 172         drm_minor_release(minor);
 173 out_unlock:
 174         mutex_unlock(&drm_global_mutex);
 175         return err;
 176 }
 177
 178 /**
 179  * Check whether DRI will run on this CPU.
 180  *
 181  * \return non-zero if the DRI will run on this CPU, or zero otherwise.
 182  */
 183 static int drm_cpu_valid(void)
 184 {
 185 #if defined(__i386__)
 186         if (boot_cpu_data.x86 == 3)
 187                 return 0;       /* No cmpxchg on a 386 */
 188 #endif
 189 #if defined(__sparc__) && !defined(__sparc_v9__)
 190         return 0;               /* No cmpxchg before v9 sparc. */
 191 #endif
 192         return 1;
 193 }
 194
 195 /**
 196  * Called whenever a process opens /dev/drm.
 197  *
 198  * \param inode device inode.
 199  * \param filp file pointer.
 200  * \param dev device.
 201  * \return zero on success or a negative number on failure.
 202  *
 203  * Creates and initializes a drm_file structure for the file private data in \p
 204  * filp and add it into the double linked list in \p dev.
 205  */
 206 static int drm_open_helper(struct inode *inode, struct file *filp,
 207                            struct drm_device * dev)
 208 {
 209         int minor_id = iminor(inode);
 210         struct drm_file *priv;
 211         int ret;
 212
 213         if (filp->f_flags & O_EXCL)
 214                 return -EBUSY;  /* No exclusive opens */
 215         if (!drm_cpu_valid())
 216                 return -EINVAL;
 217         if (dev->switch_power_state != DRM_SWITCH_POWER_ON && dev->switch_power_state != DRM_SWITCH_POWER_DYNAMIC_OFF)
 218                 return -EINVAL;
 219
 220         DRM_DEBUG("pid = %d, minor = %d\n", task_pid_nr(current), minor_id);
 221
 222         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 223         if (!priv)
 224                 return -ENOMEM;
 225
 226         filp->private_data = priv;
 227         priv->filp = filp;
 228         priv->uid = current_euid();
 229         priv->pid = get_pid(task_pid(current));
 230         priv->minor = idr_find(&drm_minors_idr, minor_id);
 231         if (!priv->minor) {
 232                 ret = -ENODEV;
 233                 goto out_put_pid;
 234         }
 235
 236         /* for compatibility root is always authenticated */
 237         priv->always_authenticated = capable(CAP_SYS_ADMIN);
 238         priv->authenticated = priv->always_authenticated;
 239         priv->lock_count = 0;
 240
 241         INIT_LIST_HEAD(&priv->lhead);
 242         INIT_LIST_HEAD(&priv->fbs);
 243         mutex_init(&priv->fbs_lock);
 244         INIT_LIST_HEAD(&priv->event_list);
 245         init_waitqueue_head(&priv->event_wait);
 246         priv->event_space = 4096; /* set aside 4k for event buffer */
 247
 248         if (dev->driver->driver_features & DRIVER_GEM)
 249                 drm_gem_open(dev, priv);
 250
 251         if (drm_core_check_feature(dev, DRIVER_PRIME))
 252                 drm_prime_init_file_private(&priv->prime);
 253
 254         if (dev->driver->open) {
 255                 ret = dev->driver->open(dev, priv);
 256                 if (ret < 0)
 257                         goto out_prime_destroy;
 258         }
 259
 260         /* if there is no current master make this fd it, but do not create
 261          * any master object for render clients */
 262         mutex_lock(&dev->struct_mutex);
 263         if (!priv->minor->master && !drm_is_render_client(priv)) {
 264                 /* create a new master */
 265                 priv->minor->master = drm_master_create(priv->minor);
 266                 if (!priv->minor->master) {
 267                         mutex_unlock(&dev->struct_mutex);
 268                         ret = -ENOMEM;
 269                         goto out_close;
 270                 }
 271
 272                 priv->is_master = 1;
 273                 /* take another reference for the copy in the local file priv */
 274                 priv->master = drm_master_get(priv->minor->master);
 275
 276                 priv->authenticated = 1;
 277
 278                 mutex_unlock(&dev->struct_mutex);
 279                 if (dev->driver->master_create) {
 280                         ret = dev->driver->master_create(dev, priv->master);
 281                         if (ret) {
 282                                 mutex_lock(&dev->struct_mutex);
 283                                 /* drop both references if this fails */
 284                                 drm_master_put(&priv->minor->master);
 285                                 drm_master_put(&priv->master);
 286                                 mutex_unlock(&dev->struct_mutex);
 287                                 goto out_close;
 288                         }
 289                 }
 290                 mutex_lock(&dev->struct_mutex);
 291                 if (dev->driver->master_set) {
 292                         ret = dev->driver->master_set(dev, priv, true);
 293                         if (ret) {
 294                                 /* drop both references if this fails */
 295                                 drm_master_put(&priv->minor->master);
 296                                 drm_master_put(&priv->master);
 297                                 mutex_unlock(&dev->struct_mutex);
 298                                 goto out_close;
 299                         }
 300                 }
 301         } else if (!drm_is_render_client(priv)) {
 302                 /* get a reference to the master */
 303                 priv->master = drm_master_get(priv->minor->master);
 304         }
 305         mutex_unlock(&dev->struct_mutex);
 306
 307         mutex_lock(&dev->struct_mutex);
 308         list_add(&priv->lhead, &dev->filelist);
 309         mutex_unlock(&dev->struct_mutex);
 310
 311 #ifdef __alpha__
 312         /*
 313          * Default the hose
 314          */
 315         if (!dev->hose) {
 316                 struct pci_dev *pci_dev;
 317                 pci_dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
 318                 if (pci_dev) {
 319                         dev->hose = pci_dev->sysdata;
 320                         pci_dev_put(pci_dev);
 321                 }
 322                 if (!dev->hose) {
 323                         struct pci_bus *b = pci_bus_b(pci_root_buses.next);
 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_minor *minor = file_priv->minor;
 463         struct drm_device *dev = minor->dev;
 464         int retcode = 0;
 465
 466         mutex_lock(&drm_global_mutex);
 467
 468         DRM_DEBUG("open_count = %d\n", dev->open_count);
 469
 470         if (dev->driver->preclose)
 471                 dev->driver->preclose(dev, file_priv);
 472
 473         /* ========================================================
 474          * Begin inline drm_release
 475          */
 476
 477         DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
 478                   task_pid_nr(current),
 479                   (long)old_encode_dev(file_priv->minor->device),
 480                   dev->open_count);
 481
 482         /* Release any auth tokens that might point to this file_priv,
 483            (do that under the drm_global_mutex) */
 484         if (file_priv->magic)
 485                 (void) drm_remove_magic(file_priv->master, file_priv->magic);
 486
 487         /* if the master has gone away we can't do anything with the lock */
 488         if (file_priv->minor->master)
 489                 drm_master_release(dev, filp);
 490
 491         if (drm_core_check_feature(dev, DRIVER_HAVE_DMA))
 492                 drm_core_reclaim_buffers(dev, file_priv);
 493
 494         drm_events_release(file_priv);
 495
 496         if (dev->driver->driver_features & DRIVER_MODESET)
 497                 drm_fb_release(file_priv);
 498
 499         if (dev->driver->driver_features & DRIVER_GEM)
 500                 drm_gem_release(dev, file_priv);
 501
 502         mutex_lock(&dev->ctxlist_mutex);
 503         if (!list_empty(&dev->ctxlist)) {
 504                 struct drm_ctx_list *pos, *n;
 505
 506                 list_for_each_entry_safe(pos, n, &dev->ctxlist, head) {
 507                         if (pos->tag == file_priv &&
 508                             pos->handle != DRM_KERNEL_CONTEXT) {
 509                                 if (dev->driver->context_dtor)
 510                                         dev->driver->context_dtor(dev,
 511                                                                   pos->handle);
 512
 513                                 drm_ctxbitmap_free(dev, pos->handle);
 514
 515                                 list_del(&pos->head);
 516                                 kfree(pos);
 517                         }
 518                 }
 519         }
 520         mutex_unlock(&dev->ctxlist_mutex);
 521
 522         mutex_lock(&dev->struct_mutex);
 523
 524         if (file_priv->is_master) {
 525                 struct drm_master *master = file_priv->master;
 526                 struct drm_file *temp;
 527                 list_for_each_entry(temp, &dev->filelist, lhead) {
 528                         if ((temp->master == file_priv->master) &&
 529                             (temp != file_priv))
 530                                 temp->authenticated = temp->always_authenticated;
 531                 }
 532
 533                 /**
 534                  * Since the master is disappearing, so is the
 535                  * possibility to lock.
 536                  */
 537
 538                 if (master->lock.hw_lock) {
 539                         if (dev->sigdata.lock == master->lock.hw_lock)
 540                                 dev->sigdata.lock = NULL;
 541                         master->lock.hw_lock = NULL;
 542                         master->lock.file_priv = NULL;
 543                         wake_up_interruptible_all(&master->lock.lock_queue);
 544                 }
 545
 546                 if (file_priv->minor->master == file_priv->master) {
 547                         /* drop the reference held my the minor */
 548                         if (dev->driver->master_drop)
 549                                 dev->driver->master_drop(dev, file_priv, true);
 550                         drm_master_put(&file_priv->minor->master);
 551                 }
 552         }
 553
 554         BUG_ON(dev->dev_mapping == NULL);
 555         iput(container_of(dev->dev_mapping, struct inode, i_data));
 556
 557         /* drop the reference held my the file priv */
 558         if (file_priv->master)
 559                 drm_master_put(&file_priv->master);
 560         file_priv->is_master = 0;
 561         list_del(&file_priv->lhead);
 562         mutex_unlock(&dev->struct_mutex);
 563
 564         if (dev->driver->postclose)
 565                 dev->driver->postclose(dev, file_priv);
 566
 567
 568         if (drm_core_check_feature(dev, DRIVER_PRIME))
 569                 drm_prime_destroy_file_private(&file_priv->prime);
 570
 571         put_pid(file_priv->pid);
 572         kfree(file_priv);
 573
 574         /* ========================================================
 575          * End inline drm_release
 576          */
 577
 578         if (!--dev->open_count) {
 579                 retcode = drm_lastclose(dev);
 580                 if (drm_device_is_unplugged(dev))
 581                         drm_put_dev(dev);
 582         }
 583         mutex_unlock(&drm_global_mutex);
 584
 585         drm_minor_release(minor);
 586
 587         return retcode;
 588 }
 589 EXPORT_SYMBOL(drm_release);
 590
 591 static bool
 592 drm_dequeue_event(struct drm_file *file_priv,
 593                   size_t total, size_t max, struct drm_pending_event **out)
 594 {
 595         struct drm_device *dev = file_priv->minor->dev;
 596         struct drm_pending_event *e;
 597         unsigned long flags;
 598         bool ret = false;
 599
 600         spin_lock_irqsave(&dev->event_lock, flags);
 601
 602         *out = NULL;
 603         if (list_empty(&file_priv->event_list))
 604                 goto out;
 605         e = list_first_entry(&file_priv->event_list,
 606                              struct drm_pending_event, link);
 607         if (e->event->length + total > max)
 608                 goto out;
 609
 610         file_priv->event_space += e->event->length;
 611         list_del(&e->link);
 612         *out = e;
 613         ret = true;
 614
 615 out:
 616         spin_unlock_irqrestore(&dev->event_lock, flags);
 617         return ret;
 618 }
 619
 620 ssize_t drm_read(struct file *filp, char __user *buffer,
 621                  size_t count, loff_t *offset)
 622 {
 623         struct drm_file *file_priv = filp->private_data;
 624         struct drm_pending_event *e;
 625         size_t total;
 626         ssize_t ret;
 627
 628         ret = wait_event_interruptible(file_priv->event_wait,
 629                                        !list_empty(&file_priv->event_list));
 630         if (ret < 0)
 631                 return ret;
 632
 633         total = 0;
 634         while (drm_dequeue_event(file_priv, total, count, &e)) {
 635                 if (copy_to_user(buffer + total,
 636                                  e->event, e->event->length)) {
 637                         total = -EFAULT;
 638                         break;
 639                 }
 640
 641                 total += e->event->length;
 642                 e->destroy(e);
 643         }
 644
 645         return total;
 646 }
 647 EXPORT_SYMBOL(drm_read);
 648
 649 unsigned int drm_poll(struct file *filp, struct poll_table_struct *wait)
 650 {
 651         struct drm_file *file_priv = filp->private_data;
 652         unsigned int mask = 0;
 653
 654         poll_wait(filp, &file_priv->event_wait, wait);
 655
 656         if (!list_empty(&file_priv->event_list))
 657                 mask |= POLLIN | POLLRDNORM;
 658
 659         return mask;
 660 }
 661 EXPORT_SYMBOL(drm_poll);