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
  41 /* from BKL pushdown: note that nothing else serializes idr_find() */
  42 DEFINE_MUTEX(drm_global_mutex);
  43 EXPORT_SYMBOL(drm_global_mutex);
  44
  45 static int drm_open_helper(struct inode *inode, struct file *filp,
  46                            struct drm_device * dev);
  47
  48 static int drm_setup(struct drm_device * dev)
  49 {
  50         int i;
  51         int ret;
  52
  53         if (dev->driver->firstopen) {
  54                 ret = dev->driver->firstopen(dev);
  55                 if (ret != 0)
  56                         return ret;
  57         }
  58
  59         atomic_set(&dev->ioctl_count, 0);
  60         atomic_set(&dev->vma_count, 0);
  61
  62         if (drm_core_check_feature(dev, DRIVER_HAVE_DMA) &&
  63             !drm_core_check_feature(dev, DRIVER_MODESET)) {
  64                 dev->buf_use = 0;
  65                 atomic_set(&dev->buf_alloc, 0);
  66
  67                 i = drm_dma_setup(dev);
  68                 if (i < 0)
  69                         return i;
  70         }
  71
  72         for (i = 0; i < ARRAY_SIZE(dev->counts); i++)
  73                 atomic_set(&dev->counts[i], 0);
  74
  75         dev->sigdata.lock = NULL;
  76
  77         dev->queue_count = 0;
  78         dev->queue_reserved = 0;
  79         dev->queue_slots = 0;
  80         dev->queuelist = NULL;
  81         dev->context_flag = 0;
  82         dev->interrupt_flag = 0;
  83         dev->dma_flag = 0;
  84         dev->last_context = 0;
  85         dev->last_switch = 0;
  86         dev->last_checked = 0;
  87         init_waitqueue_head(&dev->context_wait);
  88         dev->if_version = 0;
  89
  90         dev->ctx_start = 0;
  91         dev->lck_start = 0;
  92
  93         dev->buf_async = NULL;
  94         init_waitqueue_head(&dev->buf_readers);
  95         init_waitqueue_head(&dev->buf_writers);
  96
  97         DRM_DEBUG("\n");
  98
  99         /*
 100          * The kernel's context could be created here, but is now created
 101          * in drm_dma_enqueue.  This is more resource-efficient for
 102          * hardware that does not do DMA, but may mean that
 103          * drm_select_queue fails between the time the interrupt is
 104          * initialized and the time the queues are initialized.
 105          */
 106
 107         return 0;
 108 }
 109
 110 /**
 111  * Open file.
 112  *
 113  * \param inode device inode
 114  * \param filp file pointer.
 115  * \return zero on success or a negative number on failure.
 116  *
 117  * Searches the DRM device with the same minor number, calls open_helper(), and
 118  * increments the device open count. If the open count was previous at zero,
 119  * i.e., it's the first that the device is open, then calls setup().
 120  */
 121 int drm_open(struct inode *inode, struct file *filp)
 122 {
 123         struct drm_device *dev = NULL;
 124         int minor_id = iminor(inode);
 125         struct drm_minor *minor;
 126         int retcode = 0;
 127
 128         minor = idr_find(&drm_minors_idr, minor_id);
 129         if (!minor)
 130                 return -ENODEV;
 131
 132         if (!(dev = minor->dev))
 133                 return -ENODEV;
 134
 135         retcode = drm_open_helper(inode, filp, dev);
 136         if (!retcode) {
 137                 atomic_inc(&dev->counts[_DRM_STAT_OPENS]);
 138                 if (!dev->open_count++)
 139                         retcode = drm_setup(dev);
 140         }
 141         if (!retcode) {
 142                 mutex_lock(&dev->struct_mutex);
 143                 if (minor->type == DRM_MINOR_LEGACY) {
 144                         if (dev->dev_mapping == NULL)
 145                                 dev->dev_mapping = inode->i_mapping;
 146                         else if (dev->dev_mapping != inode->i_mapping)
 147                                 retcode = -ENODEV;
 148                 }
 149                 mutex_unlock(&dev->struct_mutex);
 150         }
 151
 152         return retcode;
 153 }
 154 EXPORT_SYMBOL(drm_open);
 155
 156 /**
 157  * File \c open operation.
 158  *
 159  * \param inode device inode.
 160  * \param filp file pointer.
 161  *
 162  * Puts the dev->fops corresponding to the device minor number into
 163  * \p filp, call the \c open method, and restore the file operations.
 164  */
 165 int drm_stub_open(struct inode *inode, struct file *filp)
 166 {
 167         struct drm_device *dev = NULL;
 168         struct drm_minor *minor;
 169         int minor_id = iminor(inode);
 170         int err = -ENODEV;
 171         const struct file_operations *old_fops;
 172
 173         DRM_DEBUG("\n");
 174
 175         mutex_lock(&drm_global_mutex);
 176         minor = idr_find(&drm_minors_idr, minor_id);
 177         if (!minor)
 178                 goto out;
 179
 180         if (!(dev = minor->dev))
 181                 goto out;
 182
 183         old_fops = filp->f_op;
 184         filp->f_op = fops_get(&dev->driver->fops);
 185         if (filp->f_op == NULL) {
 186                 filp->f_op = old_fops;
 187                 goto out;
 188         }
 189         if (filp->f_op->open && (err = filp->f_op->open(inode, filp))) {
 190                 fops_put(filp->f_op);
 191                 filp->f_op = fops_get(old_fops);
 192         }
 193         fops_put(old_fops);
 194
 195 out:
 196         mutex_unlock(&drm_global_mutex);
 197         return err;
 198 }
 199
 200 /**
 201  * Check whether DRI will run on this CPU.
 202  *
 203  * \return non-zero if the DRI will run on this CPU, or zero otherwise.
 204  */
 205 static int drm_cpu_valid(void)
 206 {
 207 #if defined(__i386__)
 208         if (boot_cpu_data.x86 == 3)
 209                 return 0;       /* No cmpxchg on a 386 */
 210 #endif
 211 #if defined(__sparc__) && !defined(__sparc_v9__)
 212         return 0;               /* No cmpxchg before v9 sparc. */
 213 #endif
 214         return 1;
 215 }
 216
 217 /**
 218  * Called whenever a process opens /dev/drm.
 219  *
 220  * \param inode device inode.
 221  * \param filp file pointer.
 222  * \param dev device.
 223  * \return zero on success or a negative number on failure.
 224  *
 225  * Creates and initializes a drm_file structure for the file private data in \p
 226  * filp and add it into the double linked list in \p dev.
 227  */
 228 static int drm_open_helper(struct inode *inode, struct file *filp,
 229                            struct drm_device * dev)
 230 {
 231         int minor_id = iminor(inode);
 232         struct drm_file *priv;
 233         int ret;
 234
 235         if (filp->f_flags & O_EXCL)
 236                 return -EBUSY;  /* No exclusive opens */
 237         if (!drm_cpu_valid())
 238                 return -EINVAL;
 239
 240         DRM_DEBUG("pid = %d, minor = %d\n", task_pid_nr(current), minor_id);
 241
 242         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 243         if (!priv)
 244                 return -ENOMEM;
 245
 246         filp->private_data = priv;
 247         priv->filp = filp;
 248         priv->uid = current_euid();
 249         priv->pid = task_pid_nr(current);
 250         priv->minor = idr_find(&drm_minors_idr, minor_id);
 251         priv->ioctl_count = 0;
 252         /* for compatibility root is always authenticated */
 253         priv->authenticated = capable(CAP_SYS_ADMIN);
 254         priv->lock_count = 0;
 255
 256         INIT_LIST_HEAD(&priv->lhead);
 257         INIT_LIST_HEAD(&priv->fbs);
 258         INIT_LIST_HEAD(&priv->event_list);
 259         init_waitqueue_head(&priv->event_wait);
 260         priv->event_space = 4096; /* set aside 4k for event buffer */
 261
 262         if (dev->driver->driver_features & DRIVER_GEM)
 263                 drm_gem_open(dev, priv);
 264
 265         if (dev->driver->open) {
 266                 ret = dev->driver->open(dev, priv);
 267                 if (ret < 0)
 268                         goto out_free;
 269         }
 270
 271
 272         /* if there is no current master make this fd it */
 273         mutex_lock(&dev->struct_mutex);
 274         if (!priv->minor->master) {
 275                 /* create a new master */
 276                 priv->minor->master = drm_master_create(priv->minor);
 277                 if (!priv->minor->master) {
 278                         mutex_unlock(&dev->struct_mutex);
 279                         ret = -ENOMEM;
 280                         goto out_free;
 281                 }
 282
 283                 priv->is_master = 1;
 284                 /* take another reference for the copy in the local file priv */
 285                 priv->master = drm_master_get(priv->minor->master);
 286
 287                 priv->authenticated = 1;
 288
 289                 mutex_unlock(&dev->struct_mutex);
 290                 if (dev->driver->master_create) {
 291                         ret = dev->driver->master_create(dev, priv->master);
 292                         if (ret) {
 293                                 mutex_lock(&dev->struct_mutex);
 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_free;
 299                         }
 300                 }
 301                 mutex_lock(&dev->struct_mutex);
 302                 if (dev->driver->master_set) {
 303                         ret = dev->driver->master_set(dev, priv, true);
 304                         if (ret) {
 305                                 /* drop both references if this fails */
 306                                 drm_master_put(&priv->minor->master);
 307                                 drm_master_put(&priv->master);
 308                                 mutex_unlock(&dev->struct_mutex);
 309                                 goto out_free;
 310                         }
 311                 }
 312                 mutex_unlock(&dev->struct_mutex);
 313         } else {
 314                 /* get a reference to the master */
 315                 priv->master = drm_master_get(priv->minor->master);
 316                 mutex_unlock(&dev->struct_mutex);
 317         }
 318
 319         mutex_lock(&dev->struct_mutex);
 320         list_add(&priv->lhead, &dev->filelist);
 321         mutex_unlock(&dev->struct_mutex);
 322
 323 #ifdef __alpha__
 324         /*
 325          * Default the hose
 326          */
 327         if (!dev->hose) {
 328                 struct pci_dev *pci_dev;
 329                 pci_dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
 330                 if (pci_dev) {
 331                         dev->hose = pci_dev->sysdata;
 332                         pci_dev_put(pci_dev);
 333                 }
 334                 if (!dev->hose) {
 335                         struct pci_bus *b = pci_bus_b(pci_root_buses.next);
 336                         if (b)
 337                                 dev->hose = b->sysdata;
 338                 }
 339         }
 340 #endif
 341
 342         return 0;
 343       out_free:
 344         kfree(priv);
 345         filp->private_data = NULL;
 346         return ret;
 347 }
 348
 349 /** No-op. */
 350 int drm_fasync(int fd, struct file *filp, int on)
 351 {
 352         struct drm_file *priv = filp->private_data;
 353         struct drm_device *dev = priv->minor->dev;
 354
 355         DRM_DEBUG("fd = %d, device = 0x%lx\n", fd,
 356                   (long)old_encode_dev(priv->minor->device));
 357         return fasync_helper(fd, filp, on, &dev->buf_async);
 358 }
 359 EXPORT_SYMBOL(drm_fasync);
 360
 361 /*
 362  * Reclaim locked buffers; note that this may be a bad idea if the current
 363  * context doesn't have the hw lock...
 364  */
 365 static void drm_reclaim_locked_buffers(struct drm_device *dev, struct file *f)
 366 {
 367         struct drm_file *file_priv = f->private_data;
 368
 369         if (drm_i_have_hw_lock(dev, file_priv)) {
 370                 dev->driver->reclaim_buffers_locked(dev, file_priv);
 371         } else {
 372                 unsigned long _end = jiffies + 3 * DRM_HZ;
 373                 int locked = 0;
 374
 375                 drm_idlelock_take(&file_priv->master->lock);
 376
 377                 /*
 378                  * Wait for a while.
 379                  */
 380                 do {
 381                         spin_lock_bh(&file_priv->master->lock.spinlock);
 382                         locked = file_priv->master->lock.idle_has_lock;
 383                         spin_unlock_bh(&file_priv->master->lock.spinlock);
 384                         if (locked)
 385                                 break;
 386                         schedule();
 387                 } while (!time_after_eq(jiffies, _end));
 388
 389                 if (!locked) {
 390                         DRM_ERROR("reclaim_buffers_locked() deadlock. Please rework this\n"
 391                                   "\tdriver to use reclaim_buffers_idlelocked() instead.\n"
 392                                   "\tI will go on reclaiming the buffers anyway.\n");
 393                 }
 394
 395                 dev->driver->reclaim_buffers_locked(dev, file_priv);
 396                 drm_idlelock_release(&file_priv->master->lock);
 397         }
 398 }
 399
 400 static void drm_master_release(struct drm_device *dev, struct file *filp)
 401 {
 402         struct drm_file *file_priv = filp->private_data;
 403
 404         if (dev->driver->reclaim_buffers_locked &&
 405             file_priv->master->lock.hw_lock)
 406                 drm_reclaim_locked_buffers(dev, filp);
 407
 408         if (dev->driver->reclaim_buffers_idlelocked &&
 409             file_priv->master->lock.hw_lock) {
 410                 drm_idlelock_take(&file_priv->master->lock);
 411                 dev->driver->reclaim_buffers_idlelocked(dev, file_priv);
 412                 drm_idlelock_release(&file_priv->master->lock);
 413         }
 414
 415
 416         if (drm_i_have_hw_lock(dev, file_priv)) {
 417                 DRM_DEBUG("File %p released, freeing lock for context %d\n",
 418                           filp, _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
 419                 drm_lock_free(&file_priv->master->lock,
 420                               _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
 421         }
 422
 423         if (drm_core_check_feature(dev, DRIVER_HAVE_DMA) &&
 424             !dev->driver->reclaim_buffers_locked) {
 425                 dev->driver->reclaim_buffers(dev, file_priv);
 426         }
 427 }
 428
 429 static void drm_events_release(struct drm_file *file_priv)
 430 {
 431         struct drm_device *dev = file_priv->minor->dev;
 432         struct drm_pending_event *e, *et;
 433         struct drm_pending_vblank_event *v, *vt;
 434         unsigned long flags;
 435
 436         spin_lock_irqsave(&dev->event_lock, flags);
 437
 438         /* Remove pending flips */
 439         list_for_each_entry_safe(v, vt, &dev->vblank_event_list, base.link)
 440                 if (v->base.file_priv == file_priv) {
 441                         list_del(&v->base.link);
 442                         drm_vblank_put(dev, v->pipe);
 443                         v->base.destroy(&v->base);
 444                 }
 445
 446         /* Remove unconsumed events */
 447         list_for_each_entry_safe(e, et, &file_priv->event_list, link)
 448                 e->destroy(e);
 449
 450         spin_unlock_irqrestore(&dev->event_lock, flags);
 451 }
 452
 453 /**
 454  * Release file.
 455  *
 456  * \param inode device inode
 457  * \param file_priv DRM file private.
 458  * \return zero on success or a negative number on failure.
 459  *
 460  * If the hardware lock is held then free it, and take it again for the kernel
 461  * context since it's necessary to reclaim buffers. Unlink the file private
 462  * data from its list and free it. Decreases the open count and if it reaches
 463  * zero calls drm_lastclose().
 464  */
 465 int drm_release(struct inode *inode, struct file *filp)
 466 {
 467         struct drm_file *file_priv = filp->private_data;
 468         struct drm_device *dev = file_priv->minor->dev;
 469         int retcode = 0;
 470
 471         mutex_lock(&drm_global_mutex);
 472
 473         DRM_DEBUG("open_count = %d\n", dev->open_count);
 474
 475         if (dev->driver->preclose)
 476                 dev->driver->preclose(dev, file_priv);
 477
 478         /* ========================================================
 479          * Begin inline drm_release
 480          */
 481
 482         DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
 483                   task_pid_nr(current),
 484                   (long)old_encode_dev(file_priv->minor->device),
 485                   dev->open_count);
 486
 487         /* if the master has gone away we can't do anything with the lock */
 488         if (file_priv->minor->master)
 489                 drm_master_release(dev, filp);
 490
 491         drm_events_release(file_priv);
 492
 493         if (dev->driver->driver_features & DRIVER_GEM)
 494                 drm_gem_release(dev, file_priv);
 495
 496         if (dev->driver->driver_features & DRIVER_MODESET)
 497                 drm_fb_release(file_priv);
 498
 499         mutex_lock(&dev->ctxlist_mutex);
 500         if (!list_empty(&dev->ctxlist)) {
 501                 struct drm_ctx_list *pos, *n;
 502
 503                 list_for_each_entry_safe(pos, n, &dev->ctxlist, head) {
 504                         if (pos->tag == file_priv &&
 505                             pos->handle != DRM_KERNEL_CONTEXT) {
 506                                 if (dev->driver->context_dtor)
 507                                         dev->driver->context_dtor(dev,
 508                                                                   pos->handle);
 509
 510                                 drm_ctxbitmap_free(dev, pos->handle);
 511
 512                                 list_del(&pos->head);
 513                                 kfree(pos);
 514                                 --dev->ctx_count;
 515                         }
 516                 }
 517         }
 518         mutex_unlock(&dev->ctxlist_mutex);
 519
 520         mutex_lock(&dev->struct_mutex);
 521
 522         if (file_priv->is_master) {
 523                 struct drm_master *master = file_priv->master;
 524                 struct drm_file *temp;
 525                 list_for_each_entry(temp, &dev->filelist, lhead) {
 526                         if ((temp->master == file_priv->master) &&
 527                             (temp != file_priv))
 528                                 temp->authenticated = 0;
 529                 }
 530
 531                 /**
 532                  * Since the master is disappearing, so is the
 533                  * possibility to lock.
 534                  */
 535
 536                 if (master->lock.hw_lock) {
 537                         if (dev->sigdata.lock == master->lock.hw_lock)
 538                                 dev->sigdata.lock = NULL;
 539                         master->lock.hw_lock = NULL;
 540                         master->lock.file_priv = NULL;
 541                         wake_up_interruptible_all(&master->lock.lock_queue);
 542                 }
 543
 544                 if (file_priv->minor->master == file_priv->master) {
 545                         /* drop the reference held my the minor */
 546                         if (dev->driver->master_drop)
 547                                 dev->driver->master_drop(dev, file_priv, true);
 548                         drm_master_put(&file_priv->minor->master);
 549                 }
 550         }
 551
 552         /* drop the reference held my the file priv */
 553         drm_master_put(&file_priv->master);
 554         file_priv->is_master = 0;
 555         list_del(&file_priv->lhead);
 556         mutex_unlock(&dev->struct_mutex);
 557
 558         if (dev->driver->postclose)
 559                 dev->driver->postclose(dev, file_priv);
 560         kfree(file_priv);
 561
 562         /* ========================================================
 563          * End inline drm_release
 564          */
 565
 566         atomic_inc(&dev->counts[_DRM_STAT_CLOSES]);
 567         if (!--dev->open_count) {
 568                 if (atomic_read(&dev->ioctl_count)) {
 569                         DRM_ERROR("Device busy: %d\n",
 570                                   atomic_read(&dev->ioctl_count));
 571                         retcode = -EBUSY;
 572                 } else
 573                         retcode = drm_lastclose(dev);
 574         }
 575         mutex_unlock(&drm_global_mutex);
 576
 577         return retcode;
 578 }
 579 EXPORT_SYMBOL(drm_release);
 580
 581 static bool
 582 drm_dequeue_event(struct drm_file *file_priv,
 583                   size_t total, size_t max, struct drm_pending_event **out)
 584 {
 585         struct drm_device *dev = file_priv->minor->dev;
 586         struct drm_pending_event *e;
 587         unsigned long flags;
 588         bool ret = false;
 589
 590         spin_lock_irqsave(&dev->event_lock, flags);
 591
 592         *out = NULL;
 593         if (list_empty(&file_priv->event_list))
 594                 goto out;
 595         e = list_first_entry(&file_priv->event_list,
 596                              struct drm_pending_event, link);
 597         if (e->event->length + total > max)
 598                 goto out;
 599
 600         file_priv->event_space += e->event->length;
 601         list_del(&e->link);
 602         *out = e;
 603         ret = true;
 604
 605 out:
 606         spin_unlock_irqrestore(&dev->event_lock, flags);
 607         return ret;
 608 }
 609
 610 ssize_t drm_read(struct file *filp, char __user *buffer,
 611                  size_t count, loff_t *offset)
 612 {
 613         struct drm_file *file_priv = filp->private_data;
 614         struct drm_pending_event *e;
 615         size_t total;
 616         ssize_t ret;
 617
 618         ret = wait_event_interruptible(file_priv->event_wait,
 619                                        !list_empty(&file_priv->event_list));
 620         if (ret < 0)
 621                 return ret;
 622
 623         total = 0;
 624         while (drm_dequeue_event(file_priv, total, count, &e)) {
 625                 if (copy_to_user(buffer + total,
 626                                  e->event, e->event->length)) {
 627                         total = -EFAULT;
 628                         break;
 629                 }
 630
 631                 total += e->event->length;
 632                 e->destroy(e);
 633         }
 634
 635         return total;
 636 }
 637 EXPORT_SYMBOL(drm_read);
 638
 639 unsigned int drm_poll(struct file *filp, struct poll_table_struct *wait)
 640 {
 641         struct drm_file *file_priv = filp->private_data;
 642         unsigned int mask = 0;
 643
 644         poll_wait(filp, &file_priv->event_wait, wait);
 645
 646         if (!list_empty(&file_priv->event_list))
 647                 mask |= POLLIN | POLLRDNORM;
 648
 649         return mask;
 650 }
 651 EXPORT_SYMBOL(drm_poll);