drivers/gpu/drm/drm_fops.c

   1 /**
   2  * \file drm_fops.c
   3  * File operations for DRM
   4  *
   5  * \author Rickard E. (Rik) Faith <[email protected]>
   6  * \author Daryll Strauss <[email protected]>
   7  * \author Gareth Hughes <[email protected]>
   8  */
   9
  10 /*
  11  * Created: Mon Jan  4 08:58:31 1999 by [email protected]
  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 #include "drm_legacy.h"
  42 #include "drm_internal.h"
  43
  44 /* from BKL pushdown */
  45 DEFINE_MUTEX(drm_global_mutex);
  46
  47 static int drm_open_helper(struct file *filp, 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(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  * Check whether DRI will run on this CPU.
 117  *
 118  * \return non-zero if the DRI will run on this CPU, or zero otherwise.
 119  */
 120 static int drm_cpu_valid(void)
 121 {
 122 #if defined(__sparc__) && !defined(__sparc_v9__)
 123         return 0;               /* No cmpxchg before v9 sparc. */
 124 #endif
 125         return 1;
 126 }
 127
 128 /**
 129  * Called whenever a process opens /dev/drm.
 130  *
 131  * \param filp file pointer.
 132  * \param minor acquired minor-object.
 133  * \return zero on success or a negative number on failure.
 134  *
 135  * Creates and initializes a drm_file structure for the file private data in \p
 136  * filp and add it into the double linked list in \p dev.
 137  */
 138 static int drm_open_helper(struct file *filp, struct drm_minor *minor)
 139 {
 140         struct drm_device *dev = minor->dev;
 141         struct drm_file *priv;
 142         int ret;
 143
 144         if (filp->f_flags & O_EXCL)
 145                 return -EBUSY;  /* No exclusive opens */
 146         if (!drm_cpu_valid())
 147                 return -EINVAL;
 148         if (dev->switch_power_state != DRM_SWITCH_POWER_ON && dev->switch_power_state != DRM_SWITCH_POWER_DYNAMIC_OFF)
 149                 return -EINVAL;
 150
 151         DRM_DEBUG("pid = %d, minor = %d\n", task_pid_nr(current), minor->index);
 152
 153         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 154         if (!priv)
 155                 return -ENOMEM;
 156
 157         filp->private_data = priv;
 158         priv->filp = filp;
 159         priv->uid = current_euid();
 160         priv->pid = get_pid(task_pid(current));
 161         priv->minor = minor;
 162
 163         /* for compatibility root is always authenticated */
 164         priv->authenticated = capable(CAP_SYS_ADMIN);
 165         priv->lock_count = 0;
 166
 167         INIT_LIST_HEAD(&priv->lhead);
 168         INIT_LIST_HEAD(&priv->fbs);
 169         mutex_init(&priv->fbs_lock);
 170         INIT_LIST_HEAD(&priv->event_list);
 171         init_waitqueue_head(&priv->event_wait);
 172         priv->event_space = 4096; /* set aside 4k for event buffer */
 173
 174         if (drm_core_check_feature(dev, DRIVER_GEM))
 175                 drm_gem_open(dev, priv);
 176
 177         if (drm_core_check_feature(dev, DRIVER_PRIME))
 178                 drm_prime_init_file_private(&priv->prime);
 179
 180         if (dev->driver->open) {
 181                 ret = dev->driver->open(dev, priv);
 182                 if (ret < 0)
 183                         goto out_prime_destroy;
 184         }
 185
 186         /* if there is no current master make this fd it, but do not create
 187          * any master object for render clients */
 188         mutex_lock(&dev->master_mutex);
 189         if (drm_is_primary_client(priv) && !priv->minor->master) {
 190                 /* create a new master */
 191                 priv->minor->master = drm_master_create(priv->minor);
 192                 if (!priv->minor->master) {
 193                         ret = -ENOMEM;
 194                         goto out_close;
 195                 }
 196
 197                 priv->is_master = 1;
 198                 /* take another reference for the copy in the local file priv */
 199                 priv->master = drm_master_get(priv->minor->master);
 200                 priv->authenticated = 1;
 201
 202                 if (dev->driver->master_create) {
 203                         ret = dev->driver->master_create(dev, priv->master);
 204                         if (ret) {
 205                                 /* drop both references if this fails */
 206                                 drm_master_put(&priv->minor->master);
 207                                 drm_master_put(&priv->master);
 208                                 goto out_close;
 209                         }
 210                 }
 211                 if (dev->driver->master_set) {
 212                         ret = dev->driver->master_set(dev, priv, true);
 213                         if (ret) {
 214                                 /* drop both references if this fails */
 215                                 drm_master_put(&priv->minor->master);
 216                                 drm_master_put(&priv->master);
 217                                 goto out_close;
 218                         }
 219                 }
 220         } else if (drm_is_primary_client(priv)) {
 221                 /* get a reference to the master */
 222                 priv->master = drm_master_get(priv->minor->master);
 223         }
 224         mutex_unlock(&dev->master_mutex);
 225
 226         mutex_lock(&dev->struct_mutex);
 227         list_add(&priv->lhead, &dev->filelist);
 228         mutex_unlock(&dev->struct_mutex);
 229
 230 #ifdef __alpha__
 231         /*
 232          * Default the hose
 233          */
 234         if (!dev->hose) {
 235                 struct pci_dev *pci_dev;
 236                 pci_dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
 237                 if (pci_dev) {
 238                         dev->hose = pci_dev->sysdata;
 239                         pci_dev_put(pci_dev);
 240                 }
 241                 if (!dev->hose) {
 242                         struct pci_bus *b = list_entry(pci_root_buses.next,
 243                                 struct pci_bus, node);
 244                         if (b)
 245                                 dev->hose = b->sysdata;
 246                 }
 247         }
 248 #endif
 249
 250         return 0;
 251
 252 out_close:
 253         mutex_unlock(&dev->master_mutex);
 254         if (dev->driver->postclose)
 255                 dev->driver->postclose(dev, priv);
 256 out_prime_destroy:
 257         if (drm_core_check_feature(dev, DRIVER_PRIME))
 258                 drm_prime_destroy_file_private(&priv->prime);
 259         if (drm_core_check_feature(dev, DRIVER_GEM))
 260                 drm_gem_release(dev, priv);
 261         put_pid(priv->pid);
 262         kfree(priv);
 263         filp->private_data = NULL;
 264         return ret;
 265 }
 266
 267 static void drm_master_release(struct drm_device *dev, struct file *filp)
 268 {
 269         struct drm_file *file_priv = filp->private_data;
 270
 271         if (drm_legacy_i_have_hw_lock(dev, file_priv)) {
 272                 DRM_DEBUG("File %p released, freeing lock for context %d\n",
 273                           filp, _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
 274                 drm_legacy_lock_free(&file_priv->master->lock,
 275                                      _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
 276         }
 277 }
 278
 279 static void drm_events_release(struct drm_file *file_priv)
 280 {
 281         struct drm_device *dev = file_priv->minor->dev;
 282         struct drm_pending_event *e, *et;
 283         struct drm_pending_vblank_event *v, *vt;
 284         unsigned long flags;
 285
 286         spin_lock_irqsave(&dev->event_lock, flags);
 287
 288         /* Remove pending flips */
 289         list_for_each_entry_safe(v, vt, &dev->vblank_event_list, base.link)
 290                 if (v->base.file_priv == file_priv) {
 291                         list_del(&v->base.link);
 292                         drm_vblank_put(dev, v->pipe);
 293                         v->base.destroy(&v->base);
 294                 }
 295
 296         /* Remove unconsumed events */
 297         list_for_each_entry_safe(e, et, &file_priv->event_list, link) {
 298                 list_del(&e->link);
 299                 e->destroy(e);
 300         }
 301
 302         spin_unlock_irqrestore(&dev->event_lock, flags);
 303 }
 304
 305 /**
 306  * drm_legacy_dev_reinit
 307  *
 308  * Reinitializes a legacy/ums drm device in it's lastclose function.
 309  */
 310 static void drm_legacy_dev_reinit(struct drm_device *dev)
 311 {
 312         if (drm_core_check_feature(dev, DRIVER_MODESET))
 313                 return;
 314
 315         dev->sigdata.lock = NULL;
 316
 317         dev->context_flag = 0;
 318         dev->last_context = 0;
 319         dev->if_version = 0;
 320 }
 321
 322 /**
 323  * Take down the DRM device.
 324  *
 325  * \param dev DRM device structure.
 326  *
 327  * Frees every resource in \p dev.
 328  *
 329  * \sa drm_device
 330  */
 331 int drm_lastclose(struct drm_device * dev)
 332 {
 333         DRM_DEBUG("\n");
 334
 335         if (dev->driver->lastclose)
 336                 dev->driver->lastclose(dev);
 337         DRM_DEBUG("driver lastclose completed\n");
 338
 339         if (dev->irq_enabled && !drm_core_check_feature(dev, DRIVER_MODESET))
 340                 drm_irq_uninstall(dev);
 341
 342         mutex_lock(&dev->struct_mutex);
 343
 344         drm_agp_clear(dev);
 345
 346         drm_legacy_sg_cleanup(dev);
 347         drm_legacy_vma_flush(dev);
 348         drm_legacy_dma_takedown(dev);
 349
 350         mutex_unlock(&dev->struct_mutex);
 351
 352         drm_legacy_dev_reinit(dev);
 353
 354         DRM_DEBUG("lastclose completed\n");
 355         return 0;
 356 }
 357
 358 /**
 359  * Release file.
 360  *
 361  * \param inode device inode
 362  * \param file_priv DRM file private.
 363  * \return zero on success or a negative number on failure.
 364  *
 365  * If the hardware lock is held then free it, and take it again for the kernel
 366  * context since it's necessary to reclaim buffers. Unlink the file private
 367  * data from its list and free it. Decreases the open count and if it reaches
 368  * zero calls drm_lastclose().
 369  */
 370 int drm_release(struct inode *inode, struct file *filp)
 371 {
 372         struct drm_file *file_priv = filp->private_data;
 373         struct drm_minor *minor = file_priv->minor;
 374         struct drm_device *dev = minor->dev;
 375         int retcode = 0;
 376
 377         mutex_lock(&drm_global_mutex);
 378
 379         DRM_DEBUG("open_count = %d\n", dev->open_count);
 380
 381         mutex_lock(&dev->struct_mutex);
 382         list_del(&file_priv->lhead);
 383         mutex_unlock(&dev->struct_mutex);
 384
 385         if (dev->driver->preclose)
 386                 dev->driver->preclose(dev, file_priv);
 387
 388         /* ========================================================
 389          * Begin inline drm_release
 390          */
 391
 392         DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
 393                   task_pid_nr(current),
 394                   (long)old_encode_dev(file_priv->minor->kdev->devt),
 395                   dev->open_count);
 396
 397         /* Release any auth tokens that might point to this file_priv,
 398            (do that under the drm_global_mutex) */
 399         if (file_priv->magic)
 400                 (void) drm_remove_magic(file_priv->master, file_priv->magic);
 401
 402         /* if the master has gone away we can't do anything with the lock */
 403         if (file_priv->minor->master)
 404                 drm_master_release(dev, filp);
 405
 406         if (drm_core_check_feature(dev, DRIVER_HAVE_DMA))
 407                 drm_legacy_reclaim_buffers(dev, file_priv);
 408
 409         drm_events_release(file_priv);
 410
 411         if (drm_core_check_feature(dev, DRIVER_MODESET))
 412                 drm_fb_release(file_priv);
 413
 414         if (drm_core_check_feature(dev, DRIVER_GEM))
 415                 drm_gem_release(dev, file_priv);
 416
 417         drm_legacy_ctxbitmap_flush(dev, file_priv);
 418
 419         mutex_lock(&dev->master_mutex);
 420
 421         if (file_priv->is_master) {
 422                 struct drm_master *master = file_priv->master;
 423
 424                 /**
 425                  * Since the master is disappearing, so is the
 426                  * possibility to lock.
 427                  */
 428                 mutex_lock(&dev->struct_mutex);
 429                 if (master->lock.hw_lock) {
 430                         if (dev->sigdata.lock == master->lock.hw_lock)
 431                                 dev->sigdata.lock = NULL;
 432                         master->lock.hw_lock = NULL;
 433                         master->lock.file_priv = NULL;
 434                         wake_up_interruptible_all(&master->lock.lock_queue);
 435                 }
 436                 mutex_unlock(&dev->struct_mutex);
 437
 438                 if (file_priv->minor->master == file_priv->master) {
 439                         /* drop the reference held my the minor */
 440                         if (dev->driver->master_drop)
 441                                 dev->driver->master_drop(dev, file_priv, true);
 442                         drm_master_put(&file_priv->minor->master);
 443                 }
 444         }
 445
 446         /* drop the master reference held by the file priv */
 447         if (file_priv->master)
 448                 drm_master_put(&file_priv->master);
 449         file_priv->is_master = 0;
 450         mutex_unlock(&dev->master_mutex);
 451
 452         if (dev->driver->postclose)
 453                 dev->driver->postclose(dev, file_priv);
 454
 455
 456         if (drm_core_check_feature(dev, DRIVER_PRIME))
 457                 drm_prime_destroy_file_private(&file_priv->prime);
 458
 459         WARN_ON(!list_empty(&file_priv->event_list));
 460
 461         put_pid(file_priv->pid);
 462         kfree(file_priv);
 463
 464         /* ========================================================
 465          * End inline drm_release
 466          */
 467
 468         if (!--dev->open_count) {
 469                 retcode = drm_lastclose(dev);
 470                 if (drm_device_is_unplugged(dev))
 471                         drm_put_dev(dev);
 472         }
 473         mutex_unlock(&drm_global_mutex);
 474
 475         drm_minor_release(minor);
 476
 477         return retcode;
 478 }
 479 EXPORT_SYMBOL(drm_release);
 480
 481 ssize_t drm_read(struct file *filp, char __user *buffer,
 482                  size_t count, loff_t *offset)
 483 {
 484         struct drm_file *file_priv = filp->private_data;
 485         struct drm_device *dev = file_priv->minor->dev;
 486         ssize_t ret = 0;
 487
 488         if (!access_ok(VERIFY_WRITE, buffer, count))
 489                 return -EFAULT;
 490
 491         spin_lock_irq(&dev->event_lock);
 492         for (;;) {
 493                 if (list_empty(&file_priv->event_list)) {
 494                         if (ret)
 495                                 break;
 496
 497                         if (filp->f_flags & O_NONBLOCK) {
 498                                 ret = -EAGAIN;
 499                                 break;
 500                         }
 501
 502                         spin_unlock_irq(&dev->event_lock);
 503                         ret = wait_event_interruptible(file_priv->event_wait,
 504                                                        !list_empty(&file_priv->event_list));
 505                         spin_lock_irq(&dev->event_lock);
 506                         if (ret < 0)
 507                                 break;
 508
 509                         ret = 0;
 510                 } else {
 511                         struct drm_pending_event *e;
 512
 513                         e = list_first_entry(&file_priv->event_list,
 514                                              struct drm_pending_event, link);
 515                         if (e->event->length + ret > count)
 516                                 break;
 517
 518                         if (__copy_to_user_inatomic(buffer + ret,
 519                                                     e->event, e->event->length)) {
 520                                 if (ret == 0)
 521                                         ret = -EFAULT;
 522                                 break;
 523                         }
 524
 525                         file_priv->event_space += e->event->length;
 526                         ret += e->event->length;
 527                         list_del(&e->link);
 528                         e->destroy(e);
 529                 }
 530         }
 531         spin_unlock_irq(&dev->event_lock);
 532
 533         return ret;
 534 }
 535 EXPORT_SYMBOL(drm_read);
 536
 537 unsigned int drm_poll(struct file *filp, struct poll_table_struct *wait)
 538 {
 539         struct drm_file *file_priv = filp->private_data;
 540         unsigned int mask = 0;
 541
 542         poll_wait(filp, &file_priv->event_wait, wait);
 543
 544         if (!list_empty(&file_priv->event_list))
 545                 mask |= POLLIN | POLLRDNORM;
 546
 547         return mask;
 548 }
 549 EXPORT_SYMBOL(drm_poll);