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