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 */
  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_minor *minor);
  48
  49 static int drm_setup(struct drm_device * dev)
  50 {
  51         int ret;
  52
  53         if (dev->driver->firstopen &&
  54             !drm_core_check_feature(dev, DRIVER_MODESET)) {
  55                 ret = dev->driver->firstopen(dev);
  56                 if (ret != 0)
  57                         return ret;
  58         }
  59
  60         ret = drm_legacy_dma_setup(dev);
  61         if (ret < 0)
  62                 return ret;
  63
  64
  65         DRM_DEBUG("\n");
  66         return 0;
  67 }
  68
  69 /**
  70  * Open file.
  71  *
  72  * \param inode device inode
  73  * \param filp file pointer.
  74  * \return zero on success or a negative number on failure.
  75  *
  76  * Searches the DRM device with the same minor number, calls open_helper(), and
  77  * increments the device open count. If the open count was previous at zero,
  78  * i.e., it's the first that the device is open, then calls setup().
  79  */
  80 int drm_open(struct inode *inode, struct file *filp)
  81 {
  82         struct drm_device *dev;
  83         struct drm_minor *minor;
  84         int retcode;
  85         int need_setup = 0;
  86
  87         minor = drm_minor_acquire(iminor(inode));
  88         if (IS_ERR(minor))
  89                 return PTR_ERR(minor);
  90
  91         dev = minor->dev;
  92         if (!dev->open_count++)
  93                 need_setup = 1;
  94
  95         /* share address_space across all char-devs of a single device */
  96         filp->f_mapping = dev->anon_inode->i_mapping;
  97
  98         retcode = drm_open_helper(inode, filp, minor);
  99         if (retcode)
 100                 goto err_undo;
 101         if (need_setup) {
 102                 retcode = drm_setup(dev);
 103                 if (retcode)
 104                         goto err_undo;
 105         }
 106         return 0;
 107
 108 err_undo:
 109         dev->open_count--;
 110         drm_minor_release(minor);
 111         return retcode;
 112 }
 113 EXPORT_SYMBOL(drm_open);
 114
 115 /**
 116  * File \c open operation.
 117  *
 118  * \param inode device inode.
 119  * \param filp file pointer.
 120  *
 121  * Puts the dev->fops corresponding to the device minor number into
 122  * \p filp, call the \c open method, and restore the file operations.
 123  */
 124 int drm_stub_open(struct inode *inode, struct file *filp)
 125 {
 126         struct drm_device *dev;
 127         struct drm_minor *minor;
 128         int err = -ENODEV;
 129         const struct file_operations *new_fops;
 130
 131         DRM_DEBUG("\n");
 132
 133         mutex_lock(&drm_global_mutex);
 134         minor = drm_minor_acquire(iminor(inode));
 135         if (IS_ERR(minor))
 136                 goto out_unlock;
 137
 138         dev = minor->dev;
 139         new_fops = fops_get(dev->driver->fops);
 140         if (!new_fops)
 141                 goto out_release;
 142
 143         replace_fops(filp, new_fops);
 144         if (filp->f_op->open)
 145                 err = filp->f_op->open(inode, filp);
 146
 147 out_release:
 148         drm_minor_release(minor);
 149 out_unlock:
 150         mutex_unlock(&drm_global_mutex);
 151         return err;
 152 }
 153
 154 /**
 155  * Check whether DRI will run on this CPU.
 156  *
 157  * \return non-zero if the DRI will run on this CPU, or zero otherwise.
 158  */
 159 static int drm_cpu_valid(void)
 160 {
 161 #if defined(__i386__)
 162         if (boot_cpu_data.x86 == 3)
 163                 return 0;       /* No cmpxchg on a 386 */
 164 #endif
 165 #if defined(__sparc__) && !defined(__sparc_v9__)
 166         return 0;               /* No cmpxchg before v9 sparc. */
 167 #endif
 168         return 1;
 169 }
 170
 171 /**
 172  * Called whenever a process opens /dev/drm.
 173  *
 174  * \param inode device inode.
 175  * \param filp file pointer.
 176  * \param minor acquired minor-object.
 177  * \return zero on success or a negative number on failure.
 178  *
 179  * Creates and initializes a drm_file structure for the file private data in \p
 180  * filp and add it into the double linked list in \p dev.
 181  */
 182 static int drm_open_helper(struct inode *inode, struct file *filp,
 183                            struct drm_minor *minor)
 184 {
 185         struct drm_device *dev = minor->dev;
 186         struct drm_file *priv;
 187         int ret;
 188
 189         if (filp->f_flags & O_EXCL)
 190                 return -EBUSY;  /* No exclusive opens */
 191         if (!drm_cpu_valid())
 192                 return -EINVAL;
 193         if (dev->switch_power_state != DRM_SWITCH_POWER_ON && dev->switch_power_state != DRM_SWITCH_POWER_DYNAMIC_OFF)
 194                 return -EINVAL;
 195
 196         DRM_DEBUG("pid = %d, minor = %d\n", task_pid_nr(current), minor->index);
 197
 198         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 199         if (!priv)
 200                 return -ENOMEM;
 201
 202         filp->private_data = priv;
 203         priv->filp = filp;
 204         priv->uid = current_euid();
 205         priv->pid = get_pid(task_pid(current));
 206         priv->minor = minor;
 207
 208         /* for compatibility root is always authenticated */
 209         priv->always_authenticated = capable(CAP_SYS_ADMIN);
 210         priv->authenticated = priv->always_authenticated;
 211         priv->lock_count = 0;
 212
 213         INIT_LIST_HEAD(&priv->lhead);
 214         INIT_LIST_HEAD(&priv->fbs);
 215         mutex_init(&priv->fbs_lock);
 216         INIT_LIST_HEAD(&priv->event_list);
 217         init_waitqueue_head(&priv->event_wait);
 218         priv->event_space = 4096; /* set aside 4k for event buffer */
 219
 220         if (dev->driver->driver_features & DRIVER_GEM)
 221                 drm_gem_open(dev, priv);
 222
 223         if (drm_core_check_feature(dev, DRIVER_PRIME))
 224                 drm_prime_init_file_private(&priv->prime);
 225
 226         if (dev->driver->open) {
 227                 ret = dev->driver->open(dev, priv);
 228                 if (ret < 0)
 229                         goto out_prime_destroy;
 230         }
 231
 232         /* if there is no current master make this fd it, but do not create
 233          * any master object for render clients */
 234         mutex_lock(&dev->struct_mutex);
 235         if (!priv->minor->master && !drm_is_render_client(priv)) {
 236                 /* create a new master */
 237                 priv->minor->master = drm_master_create(priv->minor);
 238                 if (!priv->minor->master) {
 239                         mutex_unlock(&dev->struct_mutex);
 240                         ret = -ENOMEM;
 241                         goto out_close;
 242                 }
 243
 244                 priv->is_master = 1;
 245                 /* take another reference for the copy in the local file priv */
 246                 priv->master = drm_master_get(priv->minor->master);
 247
 248                 priv->authenticated = 1;
 249
 250                 mutex_unlock(&dev->struct_mutex);
 251                 if (dev->driver->master_create) {
 252                         ret = dev->driver->master_create(dev, priv->master);
 253                         if (ret) {
 254                                 mutex_lock(&dev->struct_mutex);
 255                                 /* drop both references if this fails */
 256                                 drm_master_put(&priv->minor->master);
 257                                 drm_master_put(&priv->master);
 258                                 mutex_unlock(&dev->struct_mutex);
 259                                 goto out_close;
 260                         }
 261                 }
 262                 mutex_lock(&dev->struct_mutex);
 263                 if (dev->driver->master_set) {
 264                         ret = dev->driver->master_set(dev, priv, true);
 265                         if (ret) {
 266                                 /* drop both references if this fails */
 267                                 drm_master_put(&priv->minor->master);
 268                                 drm_master_put(&priv->master);
 269                                 mutex_unlock(&dev->struct_mutex);
 270                                 goto out_close;
 271                         }
 272                 }
 273         } else if (!drm_is_render_client(priv)) {
 274                 /* get a reference to the master */
 275                 priv->master = drm_master_get(priv->minor->master);
 276         }
 277         mutex_unlock(&dev->struct_mutex);
 278
 279         mutex_lock(&dev->struct_mutex);
 280         list_add(&priv->lhead, &dev->filelist);
 281         mutex_unlock(&dev->struct_mutex);
 282
 283 #ifdef __alpha__
 284         /*
 285          * Default the hose
 286          */
 287         if (!dev->hose) {
 288                 struct pci_dev *pci_dev;
 289                 pci_dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
 290                 if (pci_dev) {
 291                         dev->hose = pci_dev->sysdata;
 292                         pci_dev_put(pci_dev);
 293                 }
 294                 if (!dev->hose) {
 295                         struct pci_bus *b = pci_bus_b(pci_root_buses.next);
 296                         if (b)
 297                                 dev->hose = b->sysdata;
 298                 }
 299         }
 300 #endif
 301
 302         return 0;
 303
 304 out_close:
 305         if (dev->driver->postclose)
 306                 dev->driver->postclose(dev, priv);
 307 out_prime_destroy:
 308         if (drm_core_check_feature(dev, DRIVER_PRIME))
 309                 drm_prime_destroy_file_private(&priv->prime);
 310         if (dev->driver->driver_features & DRIVER_GEM)
 311                 drm_gem_release(dev, priv);
 312         put_pid(priv->pid);
 313         kfree(priv);
 314         filp->private_data = NULL;
 315         return ret;
 316 }
 317
 318 static void drm_master_release(struct drm_device *dev, struct file *filp)
 319 {
 320         struct drm_file *file_priv = filp->private_data;
 321
 322         if (drm_i_have_hw_lock(dev, file_priv)) {
 323                 DRM_DEBUG("File %p released, freeing lock for context %d\n",
 324                           filp, _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
 325                 drm_lock_free(&file_priv->master->lock,
 326                               _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
 327         }
 328 }
 329
 330 static void drm_events_release(struct drm_file *file_priv)
 331 {
 332         struct drm_device *dev = file_priv->minor->dev;
 333         struct drm_pending_event *e, *et;
 334         struct drm_pending_vblank_event *v, *vt;
 335         unsigned long flags;
 336
 337         spin_lock_irqsave(&dev->event_lock, flags);
 338
 339         /* Remove pending flips */
 340         list_for_each_entry_safe(v, vt, &dev->vblank_event_list, base.link)
 341                 if (v->base.file_priv == file_priv) {
 342                         list_del(&v->base.link);
 343                         drm_vblank_put(dev, v->pipe);
 344                         v->base.destroy(&v->base);
 345                 }
 346
 347         /* Remove unconsumed events */
 348         list_for_each_entry_safe(e, et, &file_priv->event_list, link) {
 349                 list_del(&e->link);
 350                 e->destroy(e);
 351         }
 352
 353         spin_unlock_irqrestore(&dev->event_lock, flags);
 354 }
 355
 356 /**
 357  * drm_legacy_dev_reinit
 358  *
 359  * Reinitializes a legacy/ums drm device in it's lastclose function.
 360  */
 361 static void drm_legacy_dev_reinit(struct drm_device *dev)
 362 {
 363         if (drm_core_check_feature(dev, DRIVER_MODESET))
 364                 return;
 365
 366         dev->sigdata.lock = NULL;
 367
 368         dev->context_flag = 0;
 369         dev->last_context = 0;
 370         dev->if_version = 0;
 371 }
 372
 373 /**
 374  * Take down the DRM device.
 375  *
 376  * \param dev DRM device structure.
 377  *
 378  * Frees every resource in \p dev.
 379  *
 380  * \sa drm_device
 381  */
 382 int drm_lastclose(struct drm_device * dev)
 383 {
 384         struct drm_vma_entry *vma, *vma_temp;
 385
 386         DRM_DEBUG("\n");
 387
 388         if (dev->driver->lastclose)
 389                 dev->driver->lastclose(dev);
 390         DRM_DEBUG("driver lastclose completed\n");
 391
 392         if (dev->irq_enabled && !drm_core_check_feature(dev, DRIVER_MODESET))
 393                 drm_irq_uninstall(dev);
 394
 395         mutex_lock(&dev->struct_mutex);
 396
 397         drm_agp_clear(dev);
 398
 399         drm_legacy_sg_cleanup(dev);
 400
 401         /* Clear vma list (only built for debugging) */
 402         list_for_each_entry_safe(vma, vma_temp, &dev->vmalist, head) {
 403                 list_del(&vma->head);
 404                 kfree(vma);
 405         }
 406
 407         drm_legacy_dma_takedown(dev);
 408
 409         mutex_unlock(&dev->struct_mutex);
 410
 411         drm_legacy_dev_reinit(dev);
 412
 413         DRM_DEBUG("lastclose completed\n");
 414         return 0;
 415 }
 416
 417 /**
 418  * Release file.
 419  *
 420  * \param inode device inode
 421  * \param file_priv DRM file private.
 422  * \return zero on success or a negative number on failure.
 423  *
 424  * If the hardware lock is held then free it, and take it again for the kernel
 425  * context since it's necessary to reclaim buffers. Unlink the file private
 426  * data from its list and free it. Decreases the open count and if it reaches
 427  * zero calls drm_lastclose().
 428  */
 429 int drm_release(struct inode *inode, struct file *filp)
 430 {
 431         struct drm_file *file_priv = filp->private_data;
 432         struct drm_minor *minor = file_priv->minor;
 433         struct drm_device *dev = minor->dev;
 434         int retcode = 0;
 435
 436         mutex_lock(&drm_global_mutex);
 437
 438         DRM_DEBUG("open_count = %d\n", dev->open_count);
 439
 440         if (dev->driver->preclose)
 441                 dev->driver->preclose(dev, file_priv);
 442
 443         /* ========================================================
 444          * Begin inline drm_release
 445          */
 446
 447         DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
 448                   task_pid_nr(current),
 449                   (long)old_encode_dev(file_priv->minor->kdev->devt),
 450                   dev->open_count);
 451
 452         /* Release any auth tokens that might point to this file_priv,
 453            (do that under the drm_global_mutex) */
 454         if (file_priv->magic)
 455                 (void) drm_remove_magic(file_priv->master, file_priv->magic);
 456
 457         /* if the master has gone away we can't do anything with the lock */
 458         if (file_priv->minor->master)
 459                 drm_master_release(dev, filp);
 460
 461         if (drm_core_check_feature(dev, DRIVER_HAVE_DMA))
 462                 drm_core_reclaim_buffers(dev, file_priv);
 463
 464         drm_events_release(file_priv);
 465
 466         if (dev->driver->driver_features & DRIVER_MODESET)
 467                 drm_fb_release(file_priv);
 468
 469         if (dev->driver->driver_features & DRIVER_GEM)
 470                 drm_gem_release(dev, file_priv);
 471
 472         mutex_lock(&dev->ctxlist_mutex);
 473         if (!list_empty(&dev->ctxlist)) {
 474                 struct drm_ctx_list *pos, *n;
 475
 476                 list_for_each_entry_safe(pos, n, &dev->ctxlist, head) {
 477                         if (pos->tag == file_priv &&
 478                             pos->handle != DRM_KERNEL_CONTEXT) {
 479                                 if (dev->driver->context_dtor)
 480                                         dev->driver->context_dtor(dev,
 481                                                                   pos->handle);
 482
 483                                 drm_ctxbitmap_free(dev, pos->handle);
 484
 485                                 list_del(&pos->head);
 486                                 kfree(pos);
 487                         }
 488                 }
 489         }
 490         mutex_unlock(&dev->ctxlist_mutex);
 491
 492         mutex_lock(&dev->struct_mutex);
 493
 494         if (file_priv->is_master) {
 495                 struct drm_master *master = file_priv->master;
 496                 struct drm_file *temp;
 497                 list_for_each_entry(temp, &dev->filelist, lhead) {
 498                         if ((temp->master == file_priv->master) &&
 499                             (temp != file_priv))
 500                                 temp->authenticated = temp->always_authenticated;
 501                 }
 502
 503                 /**
 504                  * Since the master is disappearing, so is the
 505                  * possibility to lock.
 506                  */
 507
 508                 if (master->lock.hw_lock) {
 509                         if (dev->sigdata.lock == master->lock.hw_lock)
 510                                 dev->sigdata.lock = NULL;
 511                         master->lock.hw_lock = NULL;
 512                         master->lock.file_priv = NULL;
 513                         wake_up_interruptible_all(&master->lock.lock_queue);
 514                 }
 515
 516                 if (file_priv->minor->master == file_priv->master) {
 517                         /* drop the reference held my the minor */
 518                         if (dev->driver->master_drop)
 519                                 dev->driver->master_drop(dev, file_priv, true);
 520                         drm_master_put(&file_priv->minor->master);
 521                 }
 522         }
 523
 524         /* drop the reference held my the file priv */
 525         if (file_priv->master)
 526                 drm_master_put(&file_priv->master);
 527         file_priv->is_master = 0;
 528         list_del(&file_priv->lhead);
 529         mutex_unlock(&dev->struct_mutex);
 530
 531         if (dev->driver->postclose)
 532                 dev->driver->postclose(dev, file_priv);
 533
 534
 535         if (drm_core_check_feature(dev, DRIVER_PRIME))
 536                 drm_prime_destroy_file_private(&file_priv->prime);
 537
 538         put_pid(file_priv->pid);
 539         kfree(file_priv);
 540
 541         /* ========================================================
 542          * End inline drm_release
 543          */
 544
 545         if (!--dev->open_count) {
 546                 retcode = drm_lastclose(dev);
 547                 if (drm_device_is_unplugged(dev))
 548                         drm_put_dev(dev);
 549         }
 550         mutex_unlock(&drm_global_mutex);
 551
 552         drm_minor_release(minor);
 553
 554         return retcode;
 555 }
 556 EXPORT_SYMBOL(drm_release);
 557
 558 static bool
 559 drm_dequeue_event(struct drm_file *file_priv,
 560                   size_t total, size_t max, struct drm_pending_event **out)
 561 {
 562         struct drm_device *dev = file_priv->minor->dev;
 563         struct drm_pending_event *e;
 564         unsigned long flags;
 565         bool ret = false;
 566
 567         spin_lock_irqsave(&dev->event_lock, flags);
 568
 569         *out = NULL;
 570         if (list_empty(&file_priv->event_list))
 571                 goto out;
 572         e = list_first_entry(&file_priv->event_list,
 573                              struct drm_pending_event, link);
 574         if (e->event->length + total > max)
 575                 goto out;
 576
 577         file_priv->event_space += e->event->length;
 578         list_del(&e->link);
 579         *out = e;
 580         ret = true;
 581
 582 out:
 583         spin_unlock_irqrestore(&dev->event_lock, flags);
 584         return ret;
 585 }
 586
 587 ssize_t drm_read(struct file *filp, char __user *buffer,
 588                  size_t count, loff_t *offset)
 589 {
 590         struct drm_file *file_priv = filp->private_data;
 591         struct drm_pending_event *e;
 592         size_t total;
 593         ssize_t ret;
 594
 595         ret = wait_event_interruptible(file_priv->event_wait,
 596                                        !list_empty(&file_priv->event_list));
 597         if (ret < 0)
 598                 return ret;
 599
 600         total = 0;
 601         while (drm_dequeue_event(file_priv, total, count, &e)) {
 602                 if (copy_to_user(buffer + total,
 603                                  e->event, e->event->length)) {
 604                         total = -EFAULT;
 605                         break;
 606                 }
 607
 608                 total += e->event->length;
 609                 e->destroy(e);
 610         }
 611
 612         return total;
 613 }
 614 EXPORT_SYMBOL(drm_read);
 615
 616 unsigned int drm_poll(struct file *filp, struct poll_table_struct *wait)
 617 {
 618         struct drm_file *file_priv = filp->private_data;
 619         unsigned int mask = 0;
 620
 621         poll_wait(filp, &file_priv->event_wait, wait);
 622
 623         if (!list_empty(&file_priv->event_list))
 624                 mask |= POLLIN | POLLRDNORM;
 625
 626         return mask;
 627 }
 628 EXPORT_SYMBOL(drm_poll);