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         struct address_space *old_imapping;
 127
 128         minor = idr_find(&drm_minors_idr, minor_id);
 129         if (!minor)
 130                 return -ENODEV;
 131
 132         if (!(dev = minor->dev))
 133                 return -ENODEV;
 134
 135         if (drm_device_is_unplugged(dev))
 136                 return -ENODEV;
 137
 138         if (!dev->open_count++)
 139                 need_setup = 1;
 140         mutex_lock(&dev->struct_mutex);
 141         old_imapping = inode->i_mapping;
 142         old_mapping = dev->dev_mapping;
 143         if (old_mapping == NULL)
 144                 dev->dev_mapping = &inode->i_data;
 145         /* ihold ensures nobody can remove inode with our i_data */
 146         ihold(container_of(dev->dev_mapping, struct inode, i_data));
 147         inode->i_mapping = dev->dev_mapping;
 148         filp->f_mapping = dev->dev_mapping;
 149         mutex_unlock(&dev->struct_mutex);
 150
 151         retcode = drm_open_helper(inode, filp, dev);
 152         if (retcode)
 153                 goto err_undo;
 154         atomic_inc(&dev->counts[_DRM_STAT_OPENS]);
 155         if (need_setup) {
 156                 retcode = drm_setup(dev);
 157                 if (retcode)
 158                         goto err_undo;
 159         }
 160         return 0;
 161
 162 err_undo:
 163         mutex_lock(&dev->struct_mutex);
 164         filp->f_mapping = old_imapping;
 165         inode->i_mapping = old_imapping;
 166         iput(container_of(dev->dev_mapping, struct inode, i_data));
 167         dev->dev_mapping = old_mapping;
 168         mutex_unlock(&dev->struct_mutex);
 169         dev->open_count--;
 170         return retcode;
 171 }
 172 EXPORT_SYMBOL(drm_open);
 173
 174 /**
 175  * File \c open operation.
 176  *
 177  * \param inode device inode.
 178  * \param filp file pointer.
 179  *
 180  * Puts the dev->fops corresponding to the device minor number into
 181  * \p filp, call the \c open method, and restore the file operations.
 182  */
 183 int drm_stub_open(struct inode *inode, struct file *filp)
 184 {
 185         struct drm_device *dev = NULL;
 186         struct drm_minor *minor;
 187         int minor_id = iminor(inode);
 188         int err = -ENODEV;
 189         const struct file_operations *old_fops;
 190
 191         DRM_DEBUG("\n");
 192
 193         mutex_lock(&drm_global_mutex);
 194         minor = idr_find(&drm_minors_idr, minor_id);
 195         if (!minor)
 196                 goto out;
 197
 198         if (!(dev = minor->dev))
 199                 goto out;
 200
 201         if (drm_device_is_unplugged(dev))
 202                 goto out;
 203
 204         old_fops = filp->f_op;
 205         filp->f_op = fops_get(dev->driver->fops);
 206         if (filp->f_op == NULL) {
 207                 filp->f_op = old_fops;
 208                 goto out;
 209         }
 210         if (filp->f_op->open && (err = filp->f_op->open(inode, filp))) {
 211                 fops_put(filp->f_op);
 212                 filp->f_op = fops_get(old_fops);
 213         }
 214         fops_put(old_fops);
 215
 216 out:
 217         mutex_unlock(&drm_global_mutex);
 218         return err;
 219 }
 220
 221 /**
 222  * Check whether DRI will run on this CPU.
 223  *
 224  * \return non-zero if the DRI will run on this CPU, or zero otherwise.
 225  */
 226 static int drm_cpu_valid(void)
 227 {
 228 #if defined(__i386__)
 229         if (boot_cpu_data.x86 == 3)
 230                 return 0;       /* No cmpxchg on a 386 */
 231 #endif
 232 #if defined(__sparc__) && !defined(__sparc_v9__)
 233         return 0;               /* No cmpxchg before v9 sparc. */
 234 #endif
 235         return 1;
 236 }
 237
 238 /**
 239  * Called whenever a process opens /dev/drm.
 240  *
 241  * \param inode device inode.
 242  * \param filp file pointer.
 243  * \param dev device.
 244  * \return zero on success or a negative number on failure.
 245  *
 246  * Creates and initializes a drm_file structure for the file private data in \p
 247  * filp and add it into the double linked list in \p dev.
 248  */
 249 static int drm_open_helper(struct inode *inode, struct file *filp,
 250                            struct drm_device * dev)
 251 {
 252         int minor_id = iminor(inode);
 253         struct drm_file *priv;
 254         int ret;
 255
 256         if (filp->f_flags & O_EXCL)
 257                 return -EBUSY;  /* No exclusive opens */
 258         if (!drm_cpu_valid())
 259                 return -EINVAL;
 260         if (dev->switch_power_state != DRM_SWITCH_POWER_ON)
 261                 return -EINVAL;
 262
 263         DRM_DEBUG("pid = %d, minor = %d\n", task_pid_nr(current), minor_id);
 264
 265         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 266         if (!priv)
 267                 return -ENOMEM;
 268
 269         filp->private_data = priv;
 270         priv->filp = filp;
 271         priv->uid = current_euid();
 272         priv->pid = get_pid(task_pid(current));
 273         priv->minor = idr_find(&drm_minors_idr, minor_id);
 274         priv->ioctl_count = 0;
 275         /* for compatibility root is always authenticated */
 276         priv->authenticated = capable(CAP_SYS_ADMIN);
 277         priv->lock_count = 0;
 278
 279         INIT_LIST_HEAD(&priv->lhead);
 280         INIT_LIST_HEAD(&priv->fbs);
 281         mutex_init(&priv->fbs_lock);
 282         INIT_LIST_HEAD(&priv->event_list);
 283         init_waitqueue_head(&priv->event_wait);
 284         priv->event_space = 4096; /* set aside 4k for event buffer */
 285
 286         if (dev->driver->driver_features & DRIVER_GEM)
 287                 drm_gem_open(dev, priv);
 288
 289         if (drm_core_check_feature(dev, DRIVER_PRIME))
 290                 drm_prime_init_file_private(&priv->prime);
 291
 292         if (dev->driver->open) {
 293                 ret = dev->driver->open(dev, priv);
 294                 if (ret < 0)
 295                         goto out_free;
 296         }
 297
 298
 299         /* if there is no current master make this fd it */
 300         mutex_lock(&dev->struct_mutex);
 301         if (!priv->minor->master) {
 302                 /* create a new master */
 303                 priv->minor->master = drm_master_create(priv->minor);
 304                 if (!priv->minor->master) {
 305                         mutex_unlock(&dev->struct_mutex);
 306                         ret = -ENOMEM;
 307                         goto out_free;
 308                 }
 309
 310                 priv->is_master = 1;
 311                 /* take another reference for the copy in the local file priv */
 312                 priv->master = drm_master_get(priv->minor->master);
 313
 314                 priv->authenticated = 1;
 315
 316                 mutex_unlock(&dev->struct_mutex);
 317                 if (dev->driver->master_create) {
 318                         ret = dev->driver->master_create(dev, priv->master);
 319                         if (ret) {
 320                                 mutex_lock(&dev->struct_mutex);
 321                                 /* drop both references if this fails */
 322                                 drm_master_put(&priv->minor->master);
 323                                 drm_master_put(&priv->master);
 324                                 mutex_unlock(&dev->struct_mutex);
 325                                 goto out_free;
 326                         }
 327                 }
 328                 mutex_lock(&dev->struct_mutex);
 329                 if (dev->driver->master_set) {
 330                         ret = dev->driver->master_set(dev, priv, true);
 331                         if (ret) {
 332                                 /* drop both references if this fails */
 333                                 drm_master_put(&priv->minor->master);
 334                                 drm_master_put(&priv->master);
 335                                 mutex_unlock(&dev->struct_mutex);
 336                                 goto out_free;
 337                         }
 338                 }
 339                 mutex_unlock(&dev->struct_mutex);
 340         } else {
 341                 /* get a reference to the master */
 342                 priv->master = drm_master_get(priv->minor->master);
 343                 mutex_unlock(&dev->struct_mutex);
 344         }
 345
 346         mutex_lock(&dev->struct_mutex);
 347         list_add(&priv->lhead, &dev->filelist);
 348         mutex_unlock(&dev->struct_mutex);
 349
 350 #ifdef __alpha__
 351         /*
 352          * Default the hose
 353          */
 354         if (!dev->hose) {
 355                 struct pci_dev *pci_dev;
 356                 pci_dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
 357                 if (pci_dev) {
 358                         dev->hose = pci_dev->sysdata;
 359                         pci_dev_put(pci_dev);
 360                 }
 361                 if (!dev->hose) {
 362                         struct pci_bus *b = pci_bus_b(pci_root_buses.next);
 363                         if (b)
 364                                 dev->hose = b->sysdata;
 365                 }
 366         }
 367 #endif
 368
 369         return 0;
 370       out_free:
 371         kfree(priv);
 372         filp->private_data = NULL;
 373         return ret;
 374 }
 375
 376 /** No-op. */
 377 int drm_fasync(int fd, struct file *filp, int on)
 378 {
 379         struct drm_file *priv = filp->private_data;
 380         struct drm_device *dev = priv->minor->dev;
 381
 382         DRM_DEBUG("fd = %d, device = 0x%lx\n", fd,
 383                   (long)old_encode_dev(priv->minor->device));
 384         return fasync_helper(fd, filp, on, &dev->buf_async);
 385 }
 386 EXPORT_SYMBOL(drm_fasync);
 387
 388 static void drm_master_release(struct drm_device *dev, struct file *filp)
 389 {
 390         struct drm_file *file_priv = filp->private_data;
 391
 392         if (drm_i_have_hw_lock(dev, file_priv)) {
 393                 DRM_DEBUG("File %p released, freeing lock for context %d\n",
 394                           filp, _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
 395                 drm_lock_free(&file_priv->master->lock,
 396                               _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
 397         }
 398 }
 399
 400 static void drm_events_release(struct drm_file *file_priv)
 401 {
 402         struct drm_device *dev = file_priv->minor->dev;
 403         struct drm_pending_event *e, *et;
 404         struct drm_pending_vblank_event *v, *vt;
 405         unsigned long flags;
 406
 407         spin_lock_irqsave(&dev->event_lock, flags);
 408
 409         /* Remove pending flips */
 410         list_for_each_entry_safe(v, vt, &dev->vblank_event_list, base.link)
 411                 if (v->base.file_priv == file_priv) {
 412                         list_del(&v->base.link);
 413                         drm_vblank_put(dev, v->pipe);
 414                         v->base.destroy(&v->base);
 415                 }
 416
 417         /* Remove unconsumed events */
 418         list_for_each_entry_safe(e, et, &file_priv->event_list, link)
 419                 e->destroy(e);
 420
 421         spin_unlock_irqrestore(&dev->event_lock, flags);
 422 }
 423
 424 /**
 425  * Release file.
 426  *
 427  * \param inode device inode
 428  * \param file_priv DRM file private.
 429  * \return zero on success or a negative number on failure.
 430  *
 431  * If the hardware lock is held then free it, and take it again for the kernel
 432  * context since it's necessary to reclaim buffers. Unlink the file private
 433  * data from its list and free it. Decreases the open count and if it reaches
 434  * zero calls drm_lastclose().
 435  */
 436 int drm_release(struct inode *inode, struct file *filp)
 437 {
 438         struct drm_file *file_priv = filp->private_data;
 439         struct drm_device *dev = file_priv->minor->dev;
 440         int retcode = 0;
 441
 442         mutex_lock(&drm_global_mutex);
 443
 444         DRM_DEBUG("open_count = %d\n", dev->open_count);
 445
 446         if (dev->driver->preclose)
 447                 dev->driver->preclose(dev, file_priv);
 448
 449         /* ========================================================
 450          * Begin inline drm_release
 451          */
 452
 453         DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
 454                   task_pid_nr(current),
 455                   (long)old_encode_dev(file_priv->minor->device),
 456                   dev->open_count);
 457
 458         /* Release any auth tokens that might point to this file_priv,
 459            (do that under the drm_global_mutex) */
 460         if (file_priv->magic)
 461                 (void) drm_remove_magic(file_priv->master, file_priv->magic);
 462
 463         /* if the master has gone away we can't do anything with the lock */
 464         if (file_priv->minor->master)
 465                 drm_master_release(dev, filp);
 466
 467         if (drm_core_check_feature(dev, DRIVER_HAVE_DMA))
 468                 drm_core_reclaim_buffers(dev, file_priv);
 469
 470         drm_events_release(file_priv);
 471
 472         if (dev->driver->driver_features & DRIVER_MODESET)
 473                 drm_fb_release(file_priv);
 474
 475         if (dev->driver->driver_features & DRIVER_GEM)
 476                 drm_gem_release(dev, file_priv);
 477
 478         mutex_lock(&dev->ctxlist_mutex);
 479         if (!list_empty(&dev->ctxlist)) {
 480                 struct drm_ctx_list *pos, *n;
 481
 482                 list_for_each_entry_safe(pos, n, &dev->ctxlist, head) {
 483                         if (pos->tag == file_priv &&
 484                             pos->handle != DRM_KERNEL_CONTEXT) {
 485                                 if (dev->driver->context_dtor)
 486                                         dev->driver->context_dtor(dev,
 487                                                                   pos->handle);
 488
 489                                 drm_ctxbitmap_free(dev, pos->handle);
 490
 491                                 list_del(&pos->head);
 492                                 kfree(pos);
 493                                 --dev->ctx_count;
 494                         }
 495                 }
 496         }
 497         mutex_unlock(&dev->ctxlist_mutex);
 498
 499         mutex_lock(&dev->struct_mutex);
 500
 501         if (file_priv->is_master) {
 502                 struct drm_master *master = file_priv->master;
 503                 struct drm_file *temp;
 504                 list_for_each_entry(temp, &dev->filelist, lhead) {
 505                         if ((temp->master == file_priv->master) &&
 506                             (temp != file_priv))
 507                                 temp->authenticated = 0;
 508                 }
 509
 510                 /**
 511                  * Since the master is disappearing, so is the
 512                  * possibility to lock.
 513                  */
 514
 515                 if (master->lock.hw_lock) {
 516                         if (dev->sigdata.lock == master->lock.hw_lock)
 517                                 dev->sigdata.lock = NULL;
 518                         master->lock.hw_lock = NULL;
 519                         master->lock.file_priv = NULL;
 520                         wake_up_interruptible_all(&master->lock.lock_queue);
 521                 }
 522
 523                 if (file_priv->minor->master == file_priv->master) {
 524                         /* drop the reference held my the minor */
 525                         if (dev->driver->master_drop)
 526                                 dev->driver->master_drop(dev, file_priv, true);
 527                         drm_master_put(&file_priv->minor->master);
 528                 }
 529         }
 530
 531         BUG_ON(dev->dev_mapping == NULL);
 532         iput(container_of(dev->dev_mapping, struct inode, i_data));
 533
 534         /* drop the reference held my the file priv */
 535         drm_master_put(&file_priv->master);
 536         file_priv->is_master = 0;
 537         list_del(&file_priv->lhead);
 538         mutex_unlock(&dev->struct_mutex);
 539
 540         if (dev->driver->postclose)
 541                 dev->driver->postclose(dev, file_priv);
 542
 543         if (drm_core_check_feature(dev, DRIVER_PRIME))
 544                 drm_prime_destroy_file_private(&file_priv->prime);
 545
 546         put_pid(file_priv->pid);
 547         kfree(file_priv);
 548
 549         /* ========================================================
 550          * End inline drm_release
 551          */
 552
 553         atomic_inc(&dev->counts[_DRM_STAT_CLOSES]);
 554         if (!--dev->open_count) {
 555                 if (atomic_read(&dev->ioctl_count)) {
 556                         DRM_ERROR("Device busy: %d\n",
 557                                   atomic_read(&dev->ioctl_count));
 558                         retcode = -EBUSY;
 559                 } else
 560                         retcode = drm_lastclose(dev);
 561                 if (drm_device_is_unplugged(dev))
 562                         drm_put_dev(dev);
 563         }
 564         mutex_unlock(&drm_global_mutex);
 565
 566         return retcode;
 567 }
 568 EXPORT_SYMBOL(drm_release);
 569
 570 static bool
 571 drm_dequeue_event(struct drm_file *file_priv,
 572                   size_t total, size_t max, struct drm_pending_event **out)
 573 {
 574         struct drm_device *dev = file_priv->minor->dev;
 575         struct drm_pending_event *e;
 576         unsigned long flags;
 577         bool ret = false;
 578
 579         spin_lock_irqsave(&dev->event_lock, flags);
 580
 581         *out = NULL;
 582         if (list_empty(&file_priv->event_list))
 583                 goto out;
 584         e = list_first_entry(&file_priv->event_list,
 585                              struct drm_pending_event, link);
 586         if (e->event->length + total > max)
 587                 goto out;
 588
 589         file_priv->event_space += e->event->length;
 590         list_del(&e->link);
 591         *out = e;
 592         ret = true;
 593
 594 out:
 595         spin_unlock_irqrestore(&dev->event_lock, flags);
 596         return ret;
 597 }
 598
 599 ssize_t drm_read(struct file *filp, char __user *buffer,
 600                  size_t count, loff_t *offset)
 601 {
 602         struct drm_file *file_priv = filp->private_data;
 603         struct drm_pending_event *e;
 604         size_t total;
 605         ssize_t ret;
 606
 607         ret = wait_event_interruptible(file_priv->event_wait,
 608                                        !list_empty(&file_priv->event_list));
 609         if (ret < 0)
 610                 return ret;
 611
 612         total = 0;
 613         while (drm_dequeue_event(file_priv, total, count, &e)) {
 614                 if (copy_to_user(buffer + total,
 615                                  e->event, e->event->length)) {
 616                         total = -EFAULT;
 617                         break;
 618                 }
 619
 620                 total += e->event->length;
 621                 e->destroy(e);
 622         }
 623
 624         return total;
 625 }
 626 EXPORT_SYMBOL(drm_read);
 627
 628 unsigned int drm_poll(struct file *filp, struct poll_table_struct *wait)
 629 {
 630         struct drm_file *file_priv = filp->private_data;
 631         unsigned int mask = 0;
 632
 633         poll_wait(filp, &file_priv->event_wait, wait);
 634
 635         if (!list_empty(&file_priv->event_list))
 636                 mask |= POLLIN | POLLRDNORM;
 637
 638         return mask;
 639 }
 640 EXPORT_SYMBOL(drm_poll);