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