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 "drmP.h"
  38 #include <linux/poll.h>
  39 #include <linux/slab.h>
  40 #include <linux/smp_lock.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                 ret = dev->driver->firstopen(dev);
  56                 if (ret != 0)
  57                         return ret;
  58         }
  59
  60         atomic_set(&dev->ioctl_count, 0);
  61         atomic_set(&dev->vma_count, 0);
  62
  63         if (drm_core_check_feature(dev, DRIVER_HAVE_DMA) &&
  64             !drm_core_check_feature(dev, DRIVER_MODESET)) {
  65                 dev->buf_use = 0;
  66                 atomic_set(&dev->buf_alloc, 0);
  67
  68                 i = drm_dma_setup(dev);
  69                 if (i < 0)
  70                         return i;
  71         }
  72
  73         for (i = 0; i < ARRAY_SIZE(dev->counts); i++)
  74                 atomic_set(&dev->counts[i], 0);
  75
  76         dev->sigdata.lock = NULL;
  77
  78         dev->queue_count = 0;
  79         dev->queue_reserved = 0;
  80         dev->queue_slots = 0;
  81         dev->queuelist = NULL;
  82         dev->context_flag = 0;
  83         dev->interrupt_flag = 0;
  84         dev->dma_flag = 0;
  85         dev->last_context = 0;
  86         dev->last_switch = 0;
  87         dev->last_checked = 0;
  88         init_waitqueue_head(&dev->context_wait);
  89         dev->if_version = 0;
  90
  91         dev->ctx_start = 0;
  92         dev->lck_start = 0;
  93
  94         dev->buf_async = NULL;
  95         init_waitqueue_head(&dev->buf_readers);
  96         init_waitqueue_head(&dev->buf_writers);
  97
  98         DRM_DEBUG("\n");
  99
 100         /*
 101          * The kernel's context could be created here, but is now created
 102          * in drm_dma_enqueue.  This is more resource-efficient for
 103          * hardware that does not do DMA, but may mean that
 104          * drm_select_queue fails between the time the interrupt is
 105          * initialized and the time the queues are initialized.
 106          */
 107
 108         return 0;
 109 }
 110
 111 /**
 112  * Open file.
 113  *
 114  * \param inode device inode
 115  * \param filp file pointer.
 116  * \return zero on success or a negative number on failure.
 117  *
 118  * Searches the DRM device with the same minor number, calls open_helper(), and
 119  * increments the device open count. If the open count was previous at zero,
 120  * i.e., it's the first that the device is open, then calls setup().
 121  */
 122 int drm_open(struct inode *inode, struct file *filp)
 123 {
 124         struct drm_device *dev = NULL;
 125         int minor_id = iminor(inode);
 126         struct drm_minor *minor;
 127         int retcode = 0;
 128
 129         minor = idr_find(&drm_minors_idr, minor_id);
 130         if (!minor)
 131                 return -ENODEV;
 132
 133         if (!(dev = minor->dev))
 134                 return -ENODEV;
 135
 136         retcode = drm_open_helper(inode, filp, dev);
 137         if (!retcode) {
 138                 atomic_inc(&dev->counts[_DRM_STAT_OPENS]);
 139                 spin_lock(&dev->count_lock);
 140                 if (!dev->open_count++) {
 141                         spin_unlock(&dev->count_lock);
 142                         retcode = drm_setup(dev);
 143                         goto out;
 144                 }
 145                 spin_unlock(&dev->count_lock);
 146         }
 147 out:
 148         if (!retcode) {
 149                 mutex_lock(&dev->struct_mutex);
 150                 if (minor->type == DRM_MINOR_LEGACY) {
 151                         if (dev->dev_mapping == NULL)
 152                                 dev->dev_mapping = inode->i_mapping;
 153                         else if (dev->dev_mapping != inode->i_mapping)
 154                                 retcode = -ENODEV;
 155                 }
 156                 mutex_unlock(&dev->struct_mutex);
 157         }
 158
 159         return retcode;
 160 }
 161 EXPORT_SYMBOL(drm_open);
 162
 163 /**
 164  * File \c open operation.
 165  *
 166  * \param inode device inode.
 167  * \param filp file pointer.
 168  *
 169  * Puts the dev->fops corresponding to the device minor number into
 170  * \p filp, call the \c open method, and restore the file operations.
 171  */
 172 int drm_stub_open(struct inode *inode, struct file *filp)
 173 {
 174         struct drm_device *dev = NULL;
 175         struct drm_minor *minor;
 176         int minor_id = iminor(inode);
 177         int err = -ENODEV;
 178         const struct file_operations *old_fops;
 179
 180         DRM_DEBUG("\n");
 181
 182         mutex_lock(&drm_global_mutex);
 183         minor = idr_find(&drm_minors_idr, minor_id);
 184         if (!minor)
 185                 goto out;
 186
 187         if (!(dev = minor->dev))
 188                 goto out;
 189
 190         old_fops = filp->f_op;
 191         filp->f_op = fops_get(&dev->driver->fops);
 192         if (filp->f_op == NULL) {
 193                 filp->f_op = old_fops;
 194                 goto out;
 195         }
 196         if (filp->f_op->open && (err = filp->f_op->open(inode, filp))) {
 197                 fops_put(filp->f_op);
 198                 filp->f_op = fops_get(old_fops);
 199         }
 200         fops_put(old_fops);
 201
 202 out:
 203         mutex_unlock(&drm_global_mutex);
 204         return err;
 205 }
 206
 207 /**
 208  * Check whether DRI will run on this CPU.
 209  *
 210  * \return non-zero if the DRI will run on this CPU, or zero otherwise.
 211  */
 212 static int drm_cpu_valid(void)
 213 {
 214 #if defined(__i386__)
 215         if (boot_cpu_data.x86 == 3)
 216                 return 0;       /* No cmpxchg on a 386 */
 217 #endif
 218 #if defined(__sparc__) && !defined(__sparc_v9__)
 219         return 0;               /* No cmpxchg before v9 sparc. */
 220 #endif
 221         return 1;
 222 }
 223
 224 /**
 225  * Called whenever a process opens /dev/drm.
 226  *
 227  * \param inode device inode.
 228  * \param filp file pointer.
 229  * \param dev device.
 230  * \return zero on success or a negative number on failure.
 231  *
 232  * Creates and initializes a drm_file structure for the file private data in \p
 233  * filp and add it into the double linked list in \p dev.
 234  */
 235 static int drm_open_helper(struct inode *inode, struct file *filp,
 236                            struct drm_device * dev)
 237 {
 238         int minor_id = iminor(inode);
 239         struct drm_file *priv;
 240         int ret;
 241
 242         if (filp->f_flags & O_EXCL)
 243                 return -EBUSY;  /* No exclusive opens */
 244         if (!drm_cpu_valid())
 245                 return -EINVAL;
 246
 247         DRM_DEBUG("pid = %d, minor = %d\n", task_pid_nr(current), minor_id);
 248
 249         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 250         if (!priv)
 251                 return -ENOMEM;
 252
 253         filp->private_data = priv;
 254         priv->filp = filp;
 255         priv->uid = current_euid();
 256         priv->pid = task_pid_nr(current);
 257         priv->minor = idr_find(&drm_minors_idr, minor_id);
 258         priv->ioctl_count = 0;
 259         /* for compatibility root is always authenticated */
 260         priv->authenticated = capable(CAP_SYS_ADMIN);
 261         priv->lock_count = 0;
 262
 263         INIT_LIST_HEAD(&priv->lhead);
 264         INIT_LIST_HEAD(&priv->fbs);
 265         INIT_LIST_HEAD(&priv->event_list);
 266         init_waitqueue_head(&priv->event_wait);
 267         priv->event_space = 4096; /* set aside 4k for event buffer */
 268
 269         if (dev->driver->driver_features & DRIVER_GEM)
 270                 drm_gem_open(dev, priv);
 271
 272         if (dev->driver->open) {
 273                 ret = dev->driver->open(dev, priv);
 274                 if (ret < 0)
 275                         goto out_free;
 276         }
 277
 278
 279         /* if there is no current master make this fd it */
 280         mutex_lock(&dev->struct_mutex);
 281         if (!priv->minor->master) {
 282                 /* create a new master */
 283                 priv->minor->master = drm_master_create(priv->minor);
 284                 if (!priv->minor->master) {
 285                         mutex_unlock(&dev->struct_mutex);
 286                         ret = -ENOMEM;
 287                         goto out_free;
 288                 }
 289
 290                 priv->is_master = 1;
 291                 /* take another reference for the copy in the local file priv */
 292                 priv->master = drm_master_get(priv->minor->master);
 293
 294                 priv->authenticated = 1;
 295
 296                 mutex_unlock(&dev->struct_mutex);
 297                 if (dev->driver->master_create) {
 298                         ret = dev->driver->master_create(dev, priv->master);
 299                         if (ret) {
 300                                 mutex_lock(&dev->struct_mutex);
 301                                 /* drop both references if this fails */
 302                                 drm_master_put(&priv->minor->master);
 303                                 drm_master_put(&priv->master);
 304                                 mutex_unlock(&dev->struct_mutex);
 305                                 goto out_free;
 306                         }
 307                 }
 308                 mutex_lock(&dev->struct_mutex);
 309                 if (dev->driver->master_set) {
 310                         ret = dev->driver->master_set(dev, priv, true);
 311                         if (ret) {
 312                                 /* drop both references if this fails */
 313                                 drm_master_put(&priv->minor->master);
 314                                 drm_master_put(&priv->master);
 315                                 mutex_unlock(&dev->struct_mutex);
 316                                 goto out_free;
 317                         }
 318                 }
 319                 mutex_unlock(&dev->struct_mutex);
 320         } else {
 321                 /* get a reference to the master */
 322                 priv->master = drm_master_get(priv->minor->master);
 323                 mutex_unlock(&dev->struct_mutex);
 324         }
 325
 326         mutex_lock(&dev->struct_mutex);
 327         list_add(&priv->lhead, &dev->filelist);
 328         mutex_unlock(&dev->struct_mutex);
 329
 330 #ifdef __alpha__
 331         /*
 332          * Default the hose
 333          */
 334         if (!dev->hose) {
 335                 struct pci_dev *pci_dev;
 336                 pci_dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
 337                 if (pci_dev) {
 338                         dev->hose = pci_dev->sysdata;
 339                         pci_dev_put(pci_dev);
 340                 }
 341                 if (!dev->hose) {
 342                         struct pci_bus *b = pci_bus_b(pci_root_buses.next);
 343                         if (b)
 344                                 dev->hose = b->sysdata;
 345                 }
 346         }
 347 #endif
 348
 349         return 0;
 350       out_free:
 351         kfree(priv);
 352         filp->private_data = NULL;
 353         return ret;
 354 }
 355
 356 /** No-op. */
 357 int drm_fasync(int fd, struct file *filp, int on)
 358 {
 359         struct drm_file *priv = filp->private_data;
 360         struct drm_device *dev = priv->minor->dev;
 361
 362         DRM_DEBUG("fd = %d, device = 0x%lx\n", fd,
 363                   (long)old_encode_dev(priv->minor->device));
 364         return fasync_helper(fd, filp, on, &dev->buf_async);
 365 }
 366 EXPORT_SYMBOL(drm_fasync);
 367
 368 /*
 369  * Reclaim locked buffers; note that this may be a bad idea if the current
 370  * context doesn't have the hw lock...
 371  */
 372 static void drm_reclaim_locked_buffers(struct drm_device *dev, struct file *f)
 373 {
 374         struct drm_file *file_priv = f->private_data;
 375
 376         if (drm_i_have_hw_lock(dev, file_priv)) {
 377                 dev->driver->reclaim_buffers_locked(dev, file_priv);
 378         } else {
 379                 unsigned long _end = jiffies + 3 * DRM_HZ;
 380                 int locked = 0;
 381
 382                 drm_idlelock_take(&file_priv->master->lock);
 383
 384                 /*
 385                  * Wait for a while.
 386                  */
 387                 do {
 388                         spin_lock_bh(&file_priv->master->lock.spinlock);
 389                         locked = file_priv->master->lock.idle_has_lock;
 390                         spin_unlock_bh(&file_priv->master->lock.spinlock);
 391                         if (locked)
 392                                 break;
 393                         schedule();
 394                 } while (!time_after_eq(jiffies, _end));
 395
 396                 if (!locked) {
 397                         DRM_ERROR("reclaim_buffers_locked() deadlock. Please rework this\n"
 398                                   "\tdriver to use reclaim_buffers_idlelocked() instead.\n"
 399                                   "\tI will go on reclaiming the buffers anyway.\n");
 400                 }
 401
 402                 dev->driver->reclaim_buffers_locked(dev, file_priv);
 403                 drm_idlelock_release(&file_priv->master->lock);
 404         }
 405 }
 406
 407 static void drm_master_release(struct drm_device *dev, struct file *filp)
 408 {
 409         struct drm_file *file_priv = filp->private_data;
 410
 411         if (dev->driver->reclaim_buffers_locked &&
 412             file_priv->master->lock.hw_lock)
 413                 drm_reclaim_locked_buffers(dev, filp);
 414
 415         if (dev->driver->reclaim_buffers_idlelocked &&
 416             file_priv->master->lock.hw_lock) {
 417                 drm_idlelock_take(&file_priv->master->lock);
 418                 dev->driver->reclaim_buffers_idlelocked(dev, file_priv);
 419                 drm_idlelock_release(&file_priv->master->lock);
 420         }
 421
 422
 423         if (drm_i_have_hw_lock(dev, file_priv)) {
 424                 DRM_DEBUG("File %p released, freeing lock for context %d\n",
 425                           filp, _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
 426                 drm_lock_free(&file_priv->master->lock,
 427                               _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
 428         }
 429
 430         if (drm_core_check_feature(dev, DRIVER_HAVE_DMA) &&
 431             !dev->driver->reclaim_buffers_locked) {
 432                 dev->driver->reclaim_buffers(dev, file_priv);
 433         }
 434 }
 435
 436 static void drm_events_release(struct drm_file *file_priv)
 437 {
 438         struct drm_device *dev = file_priv->minor->dev;
 439         struct drm_pending_event *e, *et;
 440         struct drm_pending_vblank_event *v, *vt;
 441         unsigned long flags;
 442
 443         spin_lock_irqsave(&dev->event_lock, flags);
 444
 445         /* Remove pending flips */
 446         list_for_each_entry_safe(v, vt, &dev->vblank_event_list, base.link)
 447                 if (v->base.file_priv == file_priv) {
 448                         list_del(&v->base.link);
 449                         drm_vblank_put(dev, v->pipe);
 450                         v->base.destroy(&v->base);
 451                 }
 452
 453         /* Remove unconsumed events */
 454         list_for_each_entry_safe(e, et, &file_priv->event_list, link)
 455                 e->destroy(e);
 456
 457         spin_unlock_irqrestore(&dev->event_lock, flags);
 458 }
 459
 460 /**
 461  * Release file.
 462  *
 463  * \param inode device inode
 464  * \param file_priv DRM file private.
 465  * \return zero on success or a negative number on failure.
 466  *
 467  * If the hardware lock is held then free it, and take it again for the kernel
 468  * context since it's necessary to reclaim buffers. Unlink the file private
 469  * data from its list and free it. Decreases the open count and if it reaches
 470  * zero calls drm_lastclose().
 471  */
 472 int drm_release(struct inode *inode, struct file *filp)
 473 {
 474         struct drm_file *file_priv = filp->private_data;
 475         struct drm_device *dev = file_priv->minor->dev;
 476         int retcode = 0;
 477
 478         mutex_lock(&drm_global_mutex);
 479
 480         DRM_DEBUG("open_count = %d\n", dev->open_count);
 481
 482         if (dev->driver->preclose)
 483                 dev->driver->preclose(dev, file_priv);
 484
 485         /* ========================================================
 486          * Begin inline drm_release
 487          */
 488
 489         DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
 490                   task_pid_nr(current),
 491                   (long)old_encode_dev(file_priv->minor->device),
 492                   dev->open_count);
 493
 494         /* if the master has gone away we can't do anything with the lock */
 495         if (file_priv->minor->master)
 496                 drm_master_release(dev, filp);
 497
 498         drm_events_release(file_priv);
 499
 500         if (dev->driver->driver_features & DRIVER_GEM)
 501                 drm_gem_release(dev, file_priv);
 502
 503         if (dev->driver->driver_features & DRIVER_MODESET)
 504                 drm_fb_release(file_priv);
 505
 506         mutex_lock(&dev->ctxlist_mutex);
 507         if (!list_empty(&dev->ctxlist)) {
 508                 struct drm_ctx_list *pos, *n;
 509
 510                 list_for_each_entry_safe(pos, n, &dev->ctxlist, head) {
 511                         if (pos->tag == file_priv &&
 512                             pos->handle != DRM_KERNEL_CONTEXT) {
 513                                 if (dev->driver->context_dtor)
 514                                         dev->driver->context_dtor(dev,
 515                                                                   pos->handle);
 516
 517                                 drm_ctxbitmap_free(dev, pos->handle);
 518
 519                                 list_del(&pos->head);
 520                                 kfree(pos);
 521                                 --dev->ctx_count;
 522                         }
 523                 }
 524         }
 525         mutex_unlock(&dev->ctxlist_mutex);
 526
 527         mutex_lock(&dev->struct_mutex);
 528
 529         if (file_priv->is_master) {
 530                 struct drm_master *master = file_priv->master;
 531                 struct drm_file *temp;
 532                 list_for_each_entry(temp, &dev->filelist, lhead) {
 533                         if ((temp->master == file_priv->master) &&
 534                             (temp != file_priv))
 535                                 temp->authenticated = 0;
 536                 }
 537
 538                 /**
 539                  * Since the master is disappearing, so is the
 540                  * possibility to lock.
 541                  */
 542
 543                 if (master->lock.hw_lock) {
 544                         if (dev->sigdata.lock == master->lock.hw_lock)
 545                                 dev->sigdata.lock = NULL;
 546                         master->lock.hw_lock = NULL;
 547                         master->lock.file_priv = NULL;
 548                         wake_up_interruptible_all(&master->lock.lock_queue);
 549                 }
 550
 551                 if (file_priv->minor->master == file_priv->master) {
 552                         /* drop the reference held my the minor */
 553                         if (dev->driver->master_drop)
 554                                 dev->driver->master_drop(dev, file_priv, true);
 555                         drm_master_put(&file_priv->minor->master);
 556                 }
 557         }
 558
 559         /* drop the reference held my the file priv */
 560         drm_master_put(&file_priv->master);
 561         file_priv->is_master = 0;
 562         list_del(&file_priv->lhead);
 563         mutex_unlock(&dev->struct_mutex);
 564
 565         if (dev->driver->postclose)
 566                 dev->driver->postclose(dev, file_priv);
 567         kfree(file_priv);
 568
 569         /* ========================================================
 570          * End inline drm_release
 571          */
 572
 573         atomic_inc(&dev->counts[_DRM_STAT_CLOSES]);
 574         spin_lock(&dev->count_lock);
 575         if (!--dev->open_count) {
 576                 if (atomic_read(&dev->ioctl_count)) {
 577                         DRM_ERROR("Device busy: %d\n",
 578                                   atomic_read(&dev->ioctl_count));
 579                         retcode = -EBUSY;
 580                         goto out;
 581                 }
 582                 retcode = drm_lastclose(dev);
 583         }
 584 out:
 585         spin_unlock(&dev->count_lock);
 586         mutex_unlock(&drm_global_mutex);
 587
 588         return retcode;
 589 }
 590 EXPORT_SYMBOL(drm_release);
 591
 592 static bool
 593 drm_dequeue_event(struct drm_file *file_priv,
 594                   size_t total, size_t max, struct drm_pending_event **out)
 595 {
 596         struct drm_device *dev = file_priv->minor->dev;
 597         struct drm_pending_event *e;
 598         unsigned long flags;
 599         bool ret = false;
 600
 601         spin_lock_irqsave(&dev->event_lock, flags);
 602
 603         *out = NULL;
 604         if (list_empty(&file_priv->event_list))
 605                 goto out;
 606         e = list_first_entry(&file_priv->event_list,
 607                              struct drm_pending_event, link);
 608         if (e->event->length + total > max)
 609                 goto out;
 610
 611         file_priv->event_space += e->event->length;
 612         list_del(&e->link);
 613         *out = e;
 614         ret = true;
 615
 616 out:
 617         spin_unlock_irqrestore(&dev->event_lock, flags);
 618         return ret;
 619 }
 620
 621 ssize_t drm_read(struct file *filp, char __user *buffer,
 622                  size_t count, loff_t *offset)
 623 {
 624         struct drm_file *file_priv = filp->private_data;
 625         struct drm_pending_event *e;
 626         size_t total;
 627         ssize_t ret;
 628
 629         ret = wait_event_interruptible(file_priv->event_wait,
 630                                        !list_empty(&file_priv->event_list));
 631         if (ret < 0)
 632                 return ret;
 633
 634         total = 0;
 635         while (drm_dequeue_event(file_priv, total, count, &e)) {
 636                 if (copy_to_user(buffer + total,
 637                                  e->event, e->event->length)) {
 638                         total = -EFAULT;
 639                         break;
 640                 }
 641
 642                 total += e->event->length;
 643                 e->destroy(e);
 644         }
 645
 646         return total;
 647 }
 648 EXPORT_SYMBOL(drm_read);
 649
 650 unsigned int drm_poll(struct file *filp, struct poll_table_struct *wait)
 651 {
 652         struct drm_file *file_priv = filp->private_data;
 653         unsigned int mask = 0;
 654
 655         poll_wait(filp, &file_priv->event_wait, wait);
 656
 657         if (!list_empty(&file_priv->event_list))
 658                 mask |= POLLIN | POLLRDNORM;
 659
 660         return mask;
 661 }
 662 EXPORT_SYMBOL(drm_poll);