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