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