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