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             !drm_core_check_feature(dev, DRIVER_MODESET)) {
  56                 ret = dev->driver->firstopen(dev);
  57                 if (ret != 0)
  58                         return ret;
  59         }
  60
  61         atomic_set(&dev->ioctl_count, 0);
  62         atomic_set(&dev->vma_count, 0);
  63
  64         i = drm_legacy_dma_setup(dev);
  65         if (i < 0)
  66                 return i;
  67
  68         for (i = 0; i < ARRAY_SIZE(dev->counts); i++)
  69                 atomic_set(&dev->counts[i], 0);
  70
  71         dev->sigdata.lock = NULL;
  72
  73         dev->context_flag = 0;
  74         dev->last_context = 0;
  75         dev->if_version = 0;
  76
  77         DRM_DEBUG("\n");
  78
  79         /*
  80          * The kernel's context could be created here, but is now created
  81          * in drm_dma_enqueue.  This is more resource-efficient for
  82          * hardware that does not do DMA, but may mean that
  83          * drm_select_queue fails between the time the interrupt is
  84          * initialized and the time the queues are initialized.
  85          */
  86
  87         return 0;
  88 }
  89
  90 /**
  91  * Open file.
  92  *
  93  * \param inode device inode
  94  * \param filp file pointer.
  95  * \return zero on success or a negative number on failure.
  96  *
  97  * Searches the DRM device with the same minor number, calls open_helper(), and
  98  * increments the device open count. If the open count was previous at zero,
  99  * i.e., it's the first that the device is open, then calls setup().
 100  */
 101 int drm_open(struct inode *inode, struct file *filp)
 102 {
 103         struct drm_device *dev = NULL;
 104         int minor_id = iminor(inode);
 105         struct drm_minor *minor;
 106         int retcode = 0;
 107         int need_setup = 0;
 108         struct address_space *old_mapping;
 109         struct address_space *old_imapping;
 110
 111         minor = idr_find(&drm_minors_idr, minor_id);
 112         if (!minor)
 113                 return -ENODEV;
 114
 115         if (!(dev = minor->dev))
 116                 return -ENODEV;
 117
 118         if (drm_device_is_unplugged(dev))
 119                 return -ENODEV;
 120
 121         if (!dev->open_count++)
 122                 need_setup = 1;
 123         mutex_lock(&dev->struct_mutex);
 124         old_imapping = inode->i_mapping;
 125         old_mapping = dev->dev_mapping;
 126         if (old_mapping == NULL)
 127                 dev->dev_mapping = &inode->i_data;
 128         /* ihold ensures nobody can remove inode with our i_data */
 129         ihold(container_of(dev->dev_mapping, struct inode, i_data));
 130         inode->i_mapping = dev->dev_mapping;
 131         filp->f_mapping = dev->dev_mapping;
 132         mutex_unlock(&dev->struct_mutex);
 133
 134         retcode = drm_open_helper(inode, filp, dev);
 135         if (retcode)
 136                 goto err_undo;
 137         atomic_inc(&dev->counts[_DRM_STAT_OPENS]);
 138         if (need_setup) {
 139                 retcode = drm_setup(dev);
 140                 if (retcode)
 141                         goto err_undo;
 142         }
 143         return 0;
 144
 145 err_undo:
 146         mutex_lock(&dev->struct_mutex);
 147         filp->f_mapping = old_imapping;
 148         inode->i_mapping = old_imapping;
 149         iput(container_of(dev->dev_mapping, struct inode, i_data));
 150         dev->dev_mapping = old_mapping;
 151         mutex_unlock(&dev->struct_mutex);
 152         dev->open_count--;
 153         return retcode;
 154 }
 155 EXPORT_SYMBOL(drm_open);
 156
 157 /**
 158  * File \c open operation.
 159  *
 160  * \param inode device inode.
 161  * \param filp file pointer.
 162  *
 163  * Puts the dev->fops corresponding to the device minor number into
 164  * \p filp, call the \c open method, and restore the file operations.
 165  */
 166 int drm_stub_open(struct inode *inode, struct file *filp)
 167 {
 168         struct drm_device *dev = NULL;
 169         struct drm_minor *minor;
 170         int minor_id = iminor(inode);
 171         int err = -ENODEV;
 172         const struct file_operations *old_fops;
 173
 174         DRM_DEBUG("\n");
 175
 176         mutex_lock(&drm_global_mutex);
 177         minor = idr_find(&drm_minors_idr, minor_id);
 178         if (!minor)
 179                 goto out;
 180
 181         if (!(dev = minor->dev))
 182                 goto out;
 183
 184         if (drm_device_is_unplugged(dev))
 185                 goto out;
 186
 187         old_fops = filp->f_op;
 188         filp->f_op = fops_get(dev->driver->fops);
 189         if (filp->f_op == NULL) {
 190                 filp->f_op = old_fops;
 191                 goto out;
 192         }
 193         if (filp->f_op->open && (err = filp->f_op->open(inode, filp))) {
 194                 fops_put(filp->f_op);
 195                 filp->f_op = fops_get(old_fops);
 196         }
 197         fops_put(old_fops);
 198
 199 out:
 200         mutex_unlock(&drm_global_mutex);
 201         return err;
 202 }
 203
 204 /**
 205  * Check whether DRI will run on this CPU.
 206  *
 207  * \return non-zero if the DRI will run on this CPU, or zero otherwise.
 208  */
 209 static int drm_cpu_valid(void)
 210 {
 211 #if defined(__i386__)
 212         if (boot_cpu_data.x86 == 3)
 213                 return 0;       /* No cmpxchg on a 386 */
 214 #endif
 215 #if defined(__sparc__) && !defined(__sparc_v9__)
 216         return 0;               /* No cmpxchg before v9 sparc. */
 217 #endif
 218         return 1;
 219 }
 220
 221 /**
 222  * Called whenever a process opens /dev/drm.
 223  *
 224  * \param inode device inode.
 225  * \param filp file pointer.
 226  * \param dev device.
 227  * \return zero on success or a negative number on failure.
 228  *
 229  * Creates and initializes a drm_file structure for the file private data in \p
 230  * filp and add it into the double linked list in \p dev.
 231  */
 232 static int drm_open_helper(struct inode *inode, struct file *filp,
 233                            struct drm_device * dev)
 234 {
 235         int minor_id = iminor(inode);
 236         struct drm_file *priv;
 237         int ret;
 238
 239         if (filp->f_flags & O_EXCL)
 240                 return -EBUSY;  /* No exclusive opens */
 241         if (!drm_cpu_valid())
 242                 return -EINVAL;
 243         if (dev->switch_power_state != DRM_SWITCH_POWER_ON)
 244                 return -EINVAL;
 245
 246         DRM_DEBUG("pid = %d, minor = %d\n", task_pid_nr(current), minor_id);
 247
 248         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 249         if (!priv)
 250                 return -ENOMEM;
 251
 252         filp->private_data = priv;
 253         priv->filp = filp;
 254         priv->uid = current_euid();
 255         priv->pid = get_pid(task_pid(current));
 256         priv->minor = idr_find(&drm_minors_idr, minor_id);
 257         if (!priv->minor) {
 258                 ret = -ENODEV;
 259                 goto out_put_pid;
 260         }
 261
 262         priv->ioctl_count = 0;
 263         /* for compatibility root is always authenticated */
 264         priv->authenticated = capable(CAP_SYS_ADMIN);
 265         priv->lock_count = 0;
 266
 267         INIT_LIST_HEAD(&priv->lhead);
 268         INIT_LIST_HEAD(&priv->fbs);
 269         mutex_init(&priv->fbs_lock);
 270         INIT_LIST_HEAD(&priv->event_list);
 271         init_waitqueue_head(&priv->event_wait);
 272         priv->event_space = 4096; /* set aside 4k for event buffer */
 273
 274         if (dev->driver->driver_features & DRIVER_GEM)
 275                 drm_gem_open(dev, priv);
 276
 277         if (drm_core_check_feature(dev, DRIVER_PRIME))
 278                 drm_prime_init_file_private(&priv->prime);
 279
 280         if (dev->driver->open) {
 281                 ret = dev->driver->open(dev, priv);
 282                 if (ret < 0)
 283                         goto out_prime_destroy;
 284         }
 285
 286
 287         /* if there is no current master make this fd it */
 288         mutex_lock(&dev->struct_mutex);
 289         if (!priv->minor->master) {
 290                 /* create a new master */
 291                 priv->minor->master = drm_master_create(priv->minor);
 292                 if (!priv->minor->master) {
 293                         mutex_unlock(&dev->struct_mutex);
 294                         ret = -ENOMEM;
 295                         goto out_close;
 296                 }
 297
 298                 priv->is_master = 1;
 299                 /* take another reference for the copy in the local file priv */
 300                 priv->master = drm_master_get(priv->minor->master);
 301
 302                 priv->authenticated = 1;
 303
 304                 mutex_unlock(&dev->struct_mutex);
 305                 if (dev->driver->master_create) {
 306                         ret = dev->driver->master_create(dev, priv->master);
 307                         if (ret) {
 308                                 mutex_lock(&dev->struct_mutex);
 309                                 /* drop both references if this fails */
 310                                 drm_master_put(&priv->minor->master);
 311                                 drm_master_put(&priv->master);
 312                                 mutex_unlock(&dev->struct_mutex);
 313                                 goto out_close;
 314                         }
 315                 }
 316                 mutex_lock(&dev->struct_mutex);
 317                 if (dev->driver->master_set) {
 318                         ret = dev->driver->master_set(dev, priv, true);
 319                         if (ret) {
 320                                 /* drop both references if this fails */
 321                                 drm_master_put(&priv->minor->master);
 322                                 drm_master_put(&priv->master);
 323                                 mutex_unlock(&dev->struct_mutex);
 324                                 goto out_close;
 325                         }
 326                 }
 327                 mutex_unlock(&dev->struct_mutex);
 328         } else {
 329                 /* get a reference to the master */
 330                 priv->master = drm_master_get(priv->minor->master);
 331                 mutex_unlock(&dev->struct_mutex);
 332         }
 333
 334         mutex_lock(&dev->struct_mutex);
 335         list_add(&priv->lhead, &dev->filelist);
 336         mutex_unlock(&dev->struct_mutex);
 337
 338 #ifdef __alpha__
 339         /*
 340          * Default the hose
 341          */
 342         if (!dev->hose) {
 343                 struct pci_dev *pci_dev;
 344                 pci_dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
 345                 if (pci_dev) {
 346                         dev->hose = pci_dev->sysdata;
 347                         pci_dev_put(pci_dev);
 348                 }
 349                 if (!dev->hose) {
 350                         struct pci_bus *b = pci_bus_b(pci_root_buses.next);
 351                         if (b)
 352                                 dev->hose = b->sysdata;
 353                 }
 354         }
 355 #endif
 356
 357         return 0;
 358
 359 out_close:
 360         if (dev->driver->postclose)
 361                 dev->driver->postclose(dev, priv);
 362 out_prime_destroy:
 363         if (drm_core_check_feature(dev, DRIVER_PRIME))
 364                 drm_prime_destroy_file_private(&priv->prime);
 365         if (dev->driver->driver_features & DRIVER_GEM)
 366                 drm_gem_release(dev, priv);
 367 out_put_pid:
 368         put_pid(priv->pid);
 369         kfree(priv);
 370         filp->private_data = NULL;
 371         return ret;
 372 }
 373
 374 static void drm_master_release(struct drm_device *dev, struct file *filp)
 375 {
 376         struct drm_file *file_priv = filp->private_data;
 377
 378         if (drm_i_have_hw_lock(dev, file_priv)) {
 379                 DRM_DEBUG("File %p released, freeing lock for context %d\n",
 380                           filp, _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
 381                 drm_lock_free(&file_priv->master->lock,
 382                               _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
 383         }
 384 }
 385
 386 static void drm_events_release(struct drm_file *file_priv)
 387 {
 388         struct drm_device *dev = file_priv->minor->dev;
 389         struct drm_pending_event *e, *et;
 390         struct drm_pending_vblank_event *v, *vt;
 391         unsigned long flags;
 392
 393         spin_lock_irqsave(&dev->event_lock, flags);
 394
 395         /* Remove pending flips */
 396         list_for_each_entry_safe(v, vt, &dev->vblank_event_list, base.link)
 397                 if (v->base.file_priv == file_priv) {
 398                         list_del(&v->base.link);
 399                         drm_vblank_put(dev, v->pipe);
 400                         v->base.destroy(&v->base);
 401                 }
 402
 403         /* Remove unconsumed events */
 404         list_for_each_entry_safe(e, et, &file_priv->event_list, link)
 405                 e->destroy(e);
 406
 407         spin_unlock_irqrestore(&dev->event_lock, flags);
 408 }
 409
 410 /**
 411  * Release file.
 412  *
 413  * \param inode device inode
 414  * \param file_priv DRM file private.
 415  * \return zero on success or a negative number on failure.
 416  *
 417  * If the hardware lock is held then free it, and take it again for the kernel
 418  * context since it's necessary to reclaim buffers. Unlink the file private
 419  * data from its list and free it. Decreases the open count and if it reaches
 420  * zero calls drm_lastclose().
 421  */
 422 int drm_release(struct inode *inode, struct file *filp)
 423 {
 424         struct drm_file *file_priv = filp->private_data;
 425         struct drm_device *dev = file_priv->minor->dev;
 426         int retcode = 0;
 427
 428         mutex_lock(&drm_global_mutex);
 429
 430         DRM_DEBUG("open_count = %d\n", dev->open_count);
 431
 432         if (dev->driver->preclose)
 433                 dev->driver->preclose(dev, file_priv);
 434
 435         /* ========================================================
 436          * Begin inline drm_release
 437          */
 438
 439         DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
 440                   task_pid_nr(current),
 441                   (long)old_encode_dev(file_priv->minor->device),
 442                   dev->open_count);
 443
 444         /* Release any auth tokens that might point to this file_priv,
 445            (do that under the drm_global_mutex) */
 446         if (file_priv->magic)
 447                 (void) drm_remove_magic(file_priv->master, file_priv->magic);
 448
 449         /* if the master has gone away we can't do anything with the lock */
 450         if (file_priv->minor->master)
 451                 drm_master_release(dev, filp);
 452
 453         if (drm_core_check_feature(dev, DRIVER_HAVE_DMA))
 454                 drm_core_reclaim_buffers(dev, file_priv);
 455
 456         drm_events_release(file_priv);
 457
 458         if (dev->driver->driver_features & DRIVER_MODESET)
 459                 drm_fb_release(file_priv);
 460
 461         if (dev->driver->driver_features & DRIVER_GEM)
 462                 drm_gem_release(dev, file_priv);
 463
 464         drm_legacy_ctxbitmap_release(dev, file_priv);
 465
 466         mutex_lock(&dev->struct_mutex);
 467
 468         if (file_priv->is_master) {
 469                 struct drm_master *master = file_priv->master;
 470                 struct drm_file *temp;
 471                 list_for_each_entry(temp, &dev->filelist, lhead) {
 472                         if ((temp->master == file_priv->master) &&
 473                             (temp != file_priv))
 474                                 temp->authenticated = 0;
 475                 }
 476
 477                 /**
 478                  * Since the master is disappearing, so is the
 479                  * possibility to lock.
 480                  */
 481
 482                 if (master->lock.hw_lock) {
 483                         if (dev->sigdata.lock == master->lock.hw_lock)
 484                                 dev->sigdata.lock = NULL;
 485                         master->lock.hw_lock = NULL;
 486                         master->lock.file_priv = NULL;
 487                         wake_up_interruptible_all(&master->lock.lock_queue);
 488                 }
 489
 490                 if (file_priv->minor->master == file_priv->master) {
 491                         /* drop the reference held my the minor */
 492                         if (dev->driver->master_drop)
 493                                 dev->driver->master_drop(dev, file_priv, true);
 494                         drm_master_put(&file_priv->minor->master);
 495                 }
 496         }
 497
 498         BUG_ON(dev->dev_mapping == NULL);
 499         iput(container_of(dev->dev_mapping, struct inode, i_data));
 500
 501         /* drop the reference held my the file priv */
 502         drm_master_put(&file_priv->master);
 503         file_priv->is_master = 0;
 504         list_del(&file_priv->lhead);
 505         mutex_unlock(&dev->struct_mutex);
 506
 507         if (dev->driver->postclose)
 508                 dev->driver->postclose(dev, file_priv);
 509
 510         if (drm_core_check_feature(dev, DRIVER_PRIME))
 511                 drm_prime_destroy_file_private(&file_priv->prime);
 512
 513         put_pid(file_priv->pid);
 514         kfree(file_priv);
 515
 516         /* ========================================================
 517          * End inline drm_release
 518          */
 519
 520         atomic_inc(&dev->counts[_DRM_STAT_CLOSES]);
 521         if (!--dev->open_count) {
 522                 if (atomic_read(&dev->ioctl_count)) {
 523                         DRM_ERROR("Device busy: %d\n",
 524                                   atomic_read(&dev->ioctl_count));
 525                         retcode = -EBUSY;
 526                 } else
 527                         retcode = drm_lastclose(dev);
 528                 if (drm_device_is_unplugged(dev))
 529                         drm_put_dev(dev);
 530         }
 531         mutex_unlock(&drm_global_mutex);
 532
 533         return retcode;
 534 }
 535 EXPORT_SYMBOL(drm_release);
 536
 537 static bool
 538 drm_dequeue_event(struct drm_file *file_priv,
 539                   size_t total, size_t max, struct drm_pending_event **out)
 540 {
 541         struct drm_device *dev = file_priv->minor->dev;
 542         struct drm_pending_event *e;
 543         unsigned long flags;
 544         bool ret = false;
 545
 546         spin_lock_irqsave(&dev->event_lock, flags);
 547
 548         *out = NULL;
 549         if (list_empty(&file_priv->event_list))
 550                 goto out;
 551         e = list_first_entry(&file_priv->event_list,
 552                              struct drm_pending_event, link);
 553         if (e->event->length + total > max)
 554                 goto out;
 555
 556         file_priv->event_space += e->event->length;
 557         list_del(&e->link);
 558         *out = e;
 559         ret = true;
 560
 561 out:
 562         spin_unlock_irqrestore(&dev->event_lock, flags);
 563         return ret;
 564 }
 565
 566 ssize_t drm_read(struct file *filp, char __user *buffer,
 567                  size_t count, loff_t *offset)
 568 {
 569         struct drm_file *file_priv = filp->private_data;
 570         struct drm_pending_event *e;
 571         size_t total;
 572         ssize_t ret;
 573
 574         ret = wait_event_interruptible(file_priv->event_wait,
 575                                        !list_empty(&file_priv->event_list));
 576         if (ret < 0)
 577                 return ret;
 578
 579         total = 0;
 580         while (drm_dequeue_event(file_priv, total, count, &e)) {
 581                 if (copy_to_user(buffer + total,
 582                                  e->event, e->event->length)) {
 583                         total = -EFAULT;
 584                         break;
 585                 }
 586
 587                 total += e->event->length;
 588                 e->destroy(e);
 589         }
 590
 591         return total;
 592 }
 593 EXPORT_SYMBOL(drm_read);
 594
 595 unsigned int drm_poll(struct file *filp, struct poll_table_struct *wait)
 596 {
 597         struct drm_file *file_priv = filp->private_data;
 598         unsigned int mask = 0;
 599
 600         poll_wait(filp, &file_priv->event_wait, wait);
 601
 602         if (!list_empty(&file_priv->event_list))
 603                 mask |= POLLIN | POLLRDNORM;
 604
 605         return mask;
 606 }
 607 EXPORT_SYMBOL(drm_poll);