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         if (dev->switch_power_state != DRM_SWITCH_POWER_ON)
 240                 return -EINVAL;
 241
 242         DRM_DEBUG("pid = %d, minor = %d\n", task_pid_nr(current), minor_id);
 243
 244         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 245         if (!priv)
 246                 return -ENOMEM;
 247
 248         filp->private_data = priv;
 249         priv->filp = filp;
 250         priv->uid = current_euid();
 251         priv->pid = task_pid_nr(current);
 252         priv->minor = idr_find(&drm_minors_idr, minor_id);
 253         priv->ioctl_count = 0;
 254         /* for compatibility root is always authenticated */
 255         priv->authenticated = capable(CAP_SYS_ADMIN);
 256         priv->lock_count = 0;
 257
 258         INIT_LIST_HEAD(&priv->lhead);
 259         INIT_LIST_HEAD(&priv->fbs);
 260         INIT_LIST_HEAD(&priv->event_list);
 261         init_waitqueue_head(&priv->event_wait);
 262         priv->event_space = 4096; /* set aside 4k for event buffer */
 263
 264         if (dev->driver->driver_features & DRIVER_GEM)
 265                 drm_gem_open(dev, priv);
 266
 267         if (dev->driver->open) {
 268                 ret = dev->driver->open(dev, priv);
 269                 if (ret < 0)
 270                         goto out_free;
 271         }
 272
 273
 274         /* if there is no current master make this fd it */
 275         mutex_lock(&dev->struct_mutex);
 276         if (!priv->minor->master) {
 277                 /* create a new master */
 278                 priv->minor->master = drm_master_create(priv->minor);
 279                 if (!priv->minor->master) {
 280                         mutex_unlock(&dev->struct_mutex);
 281                         ret = -ENOMEM;
 282                         goto out_free;
 283                 }
 284
 285                 priv->is_master = 1;
 286                 /* take another reference for the copy in the local file priv */
 287                 priv->master = drm_master_get(priv->minor->master);
 288
 289                 priv->authenticated = 1;
 290
 291                 mutex_unlock(&dev->struct_mutex);
 292                 if (dev->driver->master_create) {
 293                         ret = dev->driver->master_create(dev, priv->master);
 294                         if (ret) {
 295                                 mutex_lock(&dev->struct_mutex);
 296                                 /* drop both references if this fails */
 297                                 drm_master_put(&priv->minor->master);
 298                                 drm_master_put(&priv->master);
 299                                 mutex_unlock(&dev->struct_mutex);
 300                                 goto out_free;
 301                         }
 302                 }
 303                 mutex_lock(&dev->struct_mutex);
 304                 if (dev->driver->master_set) {
 305                         ret = dev->driver->master_set(dev, priv, true);
 306                         if (ret) {
 307                                 /* drop both references if this fails */
 308                                 drm_master_put(&priv->minor->master);
 309                                 drm_master_put(&priv->master);
 310                                 mutex_unlock(&dev->struct_mutex);
 311                                 goto out_free;
 312                         }
 313                 }
 314                 mutex_unlock(&dev->struct_mutex);
 315         } else {
 316                 /* get a reference to the master */
 317                 priv->master = drm_master_get(priv->minor->master);
 318                 mutex_unlock(&dev->struct_mutex);
 319         }
 320
 321         mutex_lock(&dev->struct_mutex);
 322         list_add(&priv->lhead, &dev->filelist);
 323         mutex_unlock(&dev->struct_mutex);
 324
 325 #ifdef __alpha__
 326         /*
 327          * Default the hose
 328          */
 329         if (!dev->hose) {
 330                 struct pci_dev *pci_dev;
 331                 pci_dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
 332                 if (pci_dev) {
 333                         dev->hose = pci_dev->sysdata;
 334                         pci_dev_put(pci_dev);
 335                 }
 336                 if (!dev->hose) {
 337                         struct pci_bus *b = pci_bus_b(pci_root_buses.next);
 338                         if (b)
 339                                 dev->hose = b->sysdata;
 340                 }
 341         }
 342 #endif
 343
 344         return 0;
 345       out_free:
 346         kfree(priv);
 347         filp->private_data = NULL;
 348         return ret;
 349 }
 350
 351 /** No-op. */
 352 int drm_fasync(int fd, struct file *filp, int on)
 353 {
 354         struct drm_file *priv = filp->private_data;
 355         struct drm_device *dev = priv->minor->dev;
 356
 357         DRM_DEBUG("fd = %d, device = 0x%lx\n", fd,
 358                   (long)old_encode_dev(priv->minor->device));
 359         return fasync_helper(fd, filp, on, &dev->buf_async);
 360 }
 361 EXPORT_SYMBOL(drm_fasync);
 362
 363 /*
 364  * Reclaim locked buffers; note that this may be a bad idea if the current
 365  * context doesn't have the hw lock...
 366  */
 367 static void drm_reclaim_locked_buffers(struct drm_device *dev, struct file *f)
 368 {
 369         struct drm_file *file_priv = f->private_data;
 370
 371         if (drm_i_have_hw_lock(dev, file_priv)) {
 372                 dev->driver->reclaim_buffers_locked(dev, file_priv);
 373         } else {
 374                 unsigned long _end = jiffies + 3 * DRM_HZ;
 375                 int locked = 0;
 376
 377                 drm_idlelock_take(&file_priv->master->lock);
 378
 379                 /*
 380                  * Wait for a while.
 381                  */
 382                 do {
 383                         spin_lock_bh(&file_priv->master->lock.spinlock);
 384                         locked = file_priv->master->lock.idle_has_lock;
 385                         spin_unlock_bh(&file_priv->master->lock.spinlock);
 386                         if (locked)
 387                                 break;
 388                         schedule();
 389                 } while (!time_after_eq(jiffies, _end));
 390
 391                 if (!locked) {
 392                         DRM_ERROR("reclaim_buffers_locked() deadlock. Please rework this\n"
 393                                   "\tdriver to use reclaim_buffers_idlelocked() instead.\n"
 394                                   "\tI will go on reclaiming the buffers anyway.\n");
 395                 }
 396
 397                 dev->driver->reclaim_buffers_locked(dev, file_priv);
 398                 drm_idlelock_release(&file_priv->master->lock);
 399         }
 400 }
 401
 402 static void drm_master_release(struct drm_device *dev, struct file *filp)
 403 {
 404         struct drm_file *file_priv = filp->private_data;
 405
 406         if (dev->driver->reclaim_buffers_locked &&
 407             file_priv->master->lock.hw_lock)
 408                 drm_reclaim_locked_buffers(dev, filp);
 409
 410         if (dev->driver->reclaim_buffers_idlelocked &&
 411             file_priv->master->lock.hw_lock) {
 412                 drm_idlelock_take(&file_priv->master->lock);
 413                 dev->driver->reclaim_buffers_idlelocked(dev, file_priv);
 414                 drm_idlelock_release(&file_priv->master->lock);
 415         }
 416
 417
 418         if (drm_i_have_hw_lock(dev, file_priv)) {
 419                 DRM_DEBUG("File %p released, freeing lock for context %d\n",
 420                           filp, _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
 421                 drm_lock_free(&file_priv->master->lock,
 422                               _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
 423         }
 424
 425         if (drm_core_check_feature(dev, DRIVER_HAVE_DMA) &&
 426             !dev->driver->reclaim_buffers_locked) {
 427                 dev->driver->reclaim_buffers(dev, file_priv);
 428         }
 429 }
 430
 431 static void drm_events_release(struct drm_file *file_priv)
 432 {
 433         struct drm_device *dev = file_priv->minor->dev;
 434         struct drm_pending_event *e, *et;
 435         struct drm_pending_vblank_event *v, *vt;
 436         unsigned long flags;
 437
 438         spin_lock_irqsave(&dev->event_lock, flags);
 439
 440         /* Remove pending flips */
 441         list_for_each_entry_safe(v, vt, &dev->vblank_event_list, base.link)
 442                 if (v->base.file_priv == file_priv) {
 443                         list_del(&v->base.link);
 444                         drm_vblank_put(dev, v->pipe);
 445                         v->base.destroy(&v->base);
 446                 }
 447
 448         /* Remove unconsumed events */
 449         list_for_each_entry_safe(e, et, &file_priv->event_list, link)
 450                 e->destroy(e);
 451
 452         spin_unlock_irqrestore(&dev->event_lock, flags);
 453 }
 454
 455 /**
 456  * Release file.
 457  *
 458  * \param inode device inode
 459  * \param file_priv DRM file private.
 460  * \return zero on success or a negative number on failure.
 461  *
 462  * If the hardware lock is held then free it, and take it again for the kernel
 463  * context since it's necessary to reclaim buffers. Unlink the file private
 464  * data from its list and free it. Decreases the open count and if it reaches
 465  * zero calls drm_lastclose().
 466  */
 467 int drm_release(struct inode *inode, struct file *filp)
 468 {
 469         struct drm_file *file_priv = filp->private_data;
 470         struct drm_device *dev = file_priv->minor->dev;
 471         int retcode = 0;
 472
 473         mutex_lock(&drm_global_mutex);
 474
 475         DRM_DEBUG("open_count = %d\n", dev->open_count);
 476
 477         if (dev->driver->preclose)
 478                 dev->driver->preclose(dev, file_priv);
 479
 480         /* ========================================================
 481          * Begin inline drm_release
 482          */
 483
 484         DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
 485                   task_pid_nr(current),
 486                   (long)old_encode_dev(file_priv->minor->device),
 487                   dev->open_count);
 488
 489         /* if the master has gone away we can't do anything with the lock */
 490         if (file_priv->minor->master)
 491                 drm_master_release(dev, filp);
 492
 493         drm_events_release(file_priv);
 494
 495         if (dev->driver->driver_features & DRIVER_GEM)
 496                 drm_gem_release(dev, file_priv);
 497
 498         if (dev->driver->driver_features & DRIVER_MODESET)
 499                 drm_fb_release(file_priv);
 500
 501         mutex_lock(&dev->ctxlist_mutex);
 502         if (!list_empty(&dev->ctxlist)) {
 503                 struct drm_ctx_list *pos, *n;
 504
 505                 list_for_each_entry_safe(pos, n, &dev->ctxlist, head) {
 506                         if (pos->tag == file_priv &&
 507                             pos->handle != DRM_KERNEL_CONTEXT) {
 508                                 if (dev->driver->context_dtor)
 509                                         dev->driver->context_dtor(dev,
 510                                                                   pos->handle);
 511
 512                                 drm_ctxbitmap_free(dev, pos->handle);
 513
 514                                 list_del(&pos->head);
 515                                 kfree(pos);
 516                                 --dev->ctx_count;
 517                         }
 518                 }
 519         }
 520         mutex_unlock(&dev->ctxlist_mutex);
 521
 522         mutex_lock(&dev->struct_mutex);
 523
 524         if (file_priv->is_master) {
 525                 struct drm_master *master = file_priv->master;
 526                 struct drm_file *temp;
 527                 list_for_each_entry(temp, &dev->filelist, lhead) {
 528                         if ((temp->master == file_priv->master) &&
 529                             (temp != file_priv))
 530                                 temp->authenticated = 0;
 531                 }
 532
 533                 /**
 534                  * Since the master is disappearing, so is the
 535                  * possibility to lock.
 536                  */
 537
 538                 if (master->lock.hw_lock) {
 539                         if (dev->sigdata.lock == master->lock.hw_lock)
 540                                 dev->sigdata.lock = NULL;
 541                         master->lock.hw_lock = NULL;
 542                         master->lock.file_priv = NULL;
 543                         wake_up_interruptible_all(&master->lock.lock_queue);
 544                 }
 545
 546                 if (file_priv->minor->master == file_priv->master) {
 547                         /* drop the reference held my the minor */
 548                         if (dev->driver->master_drop)
 549                                 dev->driver->master_drop(dev, file_priv, true);
 550                         drm_master_put(&file_priv->minor->master);
 551                 }
 552         }
 553
 554         /* drop the reference held my the file priv */
 555         drm_master_put(&file_priv->master);
 556         file_priv->is_master = 0;
 557         list_del(&file_priv->lhead);
 558         mutex_unlock(&dev->struct_mutex);
 559
 560         if (dev->driver->postclose)
 561                 dev->driver->postclose(dev, file_priv);
 562         kfree(file_priv);
 563
 564         /* ========================================================
 565          * End inline drm_release
 566          */
 567
 568         atomic_inc(&dev->counts[_DRM_STAT_CLOSES]);
 569         if (!--dev->open_count) {
 570                 if (atomic_read(&dev->ioctl_count)) {
 571                         DRM_ERROR("Device busy: %d\n",
 572                                   atomic_read(&dev->ioctl_count));
 573                         retcode = -EBUSY;
 574                 } else
 575                         retcode = drm_lastclose(dev);
 576         }
 577         mutex_unlock(&drm_global_mutex);
 578
 579         return retcode;
 580 }
 581 EXPORT_SYMBOL(drm_release);
 582
 583 static bool
 584 drm_dequeue_event(struct drm_file *file_priv,
 585                   size_t total, size_t max, struct drm_pending_event **out)
 586 {
 587         struct drm_device *dev = file_priv->minor->dev;
 588         struct drm_pending_event *e;
 589         unsigned long flags;
 590         bool ret = false;
 591
 592         spin_lock_irqsave(&dev->event_lock, flags);
 593
 594         *out = NULL;
 595         if (list_empty(&file_priv->event_list))
 596                 goto out;
 597         e = list_first_entry(&file_priv->event_list,
 598                              struct drm_pending_event, link);
 599         if (e->event->length + total > max)
 600                 goto out;
 601
 602         file_priv->event_space += e->event->length;
 603         list_del(&e->link);
 604         *out = e;
 605         ret = true;
 606
 607 out:
 608         spin_unlock_irqrestore(&dev->event_lock, flags);
 609         return ret;
 610 }
 611
 612 ssize_t drm_read(struct file *filp, char __user *buffer,
 613                  size_t count, loff_t *offset)
 614 {
 615         struct drm_file *file_priv = filp->private_data;
 616         struct drm_pending_event *e;
 617         size_t total;
 618         ssize_t ret;
 619
 620         ret = wait_event_interruptible(file_priv->event_wait,
 621                                        !list_empty(&file_priv->event_list));
 622         if (ret < 0)
 623                 return ret;
 624
 625         total = 0;
 626         while (drm_dequeue_event(file_priv, total, count, &e)) {
 627                 if (copy_to_user(buffer + total,
 628                                  e->event, e->event->length)) {
 629                         total = -EFAULT;
 630                         break;
 631                 }
 632
 633                 total += e->event->length;
 634                 e->destroy(e);
 635         }
 636
 637         return total;
 638 }
 639 EXPORT_SYMBOL(drm_read);
 640
 641 unsigned int drm_poll(struct file *filp, struct poll_table_struct *wait)
 642 {
 643         struct drm_file *file_priv = filp->private_data;
 644         unsigned int mask = 0;
 645
 646         poll_wait(filp, &file_priv->event_wait, wait);
 647
 648         if (!list_empty(&file_priv->event_list))
 649                 mask |= POLLIN | POLLRDNORM;
 650
 651         return mask;
 652 }
 653 EXPORT_SYMBOL(drm_poll);