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