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/smp_lock.h>
  40
  41 static int drm_open_helper(struct inode *inode, struct file *filp,
  42                            struct drm_device * dev);
  43
  44 static int drm_setup(struct drm_device * dev)
  45 {
  46         int i;
  47         int ret;
  48
  49         if (dev->driver->firstopen) {
  50                 ret = dev->driver->firstopen(dev);
  51                 if (ret != 0)
  52                         return ret;
  53         }
  54
  55         atomic_set(&dev->ioctl_count, 0);
  56         atomic_set(&dev->vma_count, 0);
  57
  58         if (drm_core_check_feature(dev, DRIVER_HAVE_DMA) &&
  59             !drm_core_check_feature(dev, DRIVER_MODESET)) {
  60                 dev->buf_use = 0;
  61                 atomic_set(&dev->buf_alloc, 0);
  62
  63                 i = drm_dma_setup(dev);
  64                 if (i < 0)
  65                         return i;
  66         }
  67
  68         for (i = 0; i < ARRAY_SIZE(dev->counts); i++)
  69                 atomic_set(&dev->counts[i], 0);
  70
  71         dev->sigdata.lock = NULL;
  72
  73         dev->queue_count = 0;
  74         dev->queue_reserved = 0;
  75         dev->queue_slots = 0;
  76         dev->queuelist = NULL;
  77         dev->context_flag = 0;
  78         dev->interrupt_flag = 0;
  79         dev->dma_flag = 0;
  80         dev->last_context = 0;
  81         dev->last_switch = 0;
  82         dev->last_checked = 0;
  83         init_waitqueue_head(&dev->context_wait);
  84         dev->if_version = 0;
  85
  86         dev->ctx_start = 0;
  87         dev->lck_start = 0;
  88
  89         dev->buf_async = NULL;
  90         init_waitqueue_head(&dev->buf_readers);
  91         init_waitqueue_head(&dev->buf_writers);
  92
  93         DRM_DEBUG("\n");
  94
  95         /*
  96          * The kernel's context could be created here, but is now created
  97          * in drm_dma_enqueue.  This is more resource-efficient for
  98          * hardware that does not do DMA, but may mean that
  99          * drm_select_queue fails between the time the interrupt is
 100          * initialized and the time the queues are initialized.
 101          */
 102
 103         return 0;
 104 }
 105
 106 /**
 107  * Open file.
 108  *
 109  * \param inode device inode
 110  * \param filp file pointer.
 111  * \return zero on success or a negative number on failure.
 112  *
 113  * Searches the DRM device with the same minor number, calls open_helper(), and
 114  * increments the device open count. If the open count was previous at zero,
 115  * i.e., it's the first that the device is open, then calls setup().
 116  */
 117 int drm_open(struct inode *inode, struct file *filp)
 118 {
 119         struct drm_device *dev = NULL;
 120         int minor_id = iminor(inode);
 121         struct drm_minor *minor;
 122         int retcode = 0;
 123
 124         minor = idr_find(&drm_minors_idr, minor_id);
 125         if (!minor)
 126                 return -ENODEV;
 127
 128         if (!(dev = minor->dev))
 129                 return -ENODEV;
 130
 131         retcode = drm_open_helper(inode, filp, dev);
 132         if (!retcode) {
 133                 atomic_inc(&dev->counts[_DRM_STAT_OPENS]);
 134                 spin_lock(&dev->count_lock);
 135                 if (!dev->open_count++) {
 136                         spin_unlock(&dev->count_lock);
 137                         retcode = drm_setup(dev);
 138                         goto out;
 139                 }
 140                 spin_unlock(&dev->count_lock);
 141         }
 142 out:
 143         mutex_lock(&dev->struct_mutex);
 144         if (minor->type == DRM_MINOR_LEGACY) {
 145                 BUG_ON((dev->dev_mapping != NULL) &&
 146                         (dev->dev_mapping != inode->i_mapping));
 147                 if (dev->dev_mapping == NULL)
 148                         dev->dev_mapping = inode->i_mapping;
 149         }
 150         mutex_unlock(&dev->struct_mutex);
 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         /* BKL pushdown: note that nothing else serializes idr_find() */
 176         lock_kernel();
 177         minor = idr_find(&drm_minors_idr, minor_id);
 178         if (!minor)
 179                 goto out;
 180
 181         if (!(dev = minor->dev))
 182                 goto out;
 183
 184         old_fops = filp->f_op;
 185         filp->f_op = fops_get(&dev->driver->fops);
 186         if (filp->f_op == NULL) {
 187                 filp->f_op = old_fops;
 188                 goto out;
 189         }
 190         if (filp->f_op->open && (err = filp->f_op->open(inode, filp))) {
 191                 fops_put(filp->f_op);
 192                 filp->f_op = fops_get(old_fops);
 193         }
 194         fops_put(old_fops);
 195
 196 out:
 197         unlock_kernel();
 198         return err;
 199 }
 200
 201 /**
 202  * Check whether DRI will run on this CPU.
 203  *
 204  * \return non-zero if the DRI will run on this CPU, or zero otherwise.
 205  */
 206 static int drm_cpu_valid(void)
 207 {
 208 #if defined(__i386__)
 209         if (boot_cpu_data.x86 == 3)
 210                 return 0;       /* No cmpxchg on a 386 */
 211 #endif
 212 #if defined(__sparc__) && !defined(__sparc_v9__)
 213         return 0;               /* No cmpxchg before v9 sparc. */
 214 #endif
 215         return 1;
 216 }
 217
 218 /**
 219  * Called whenever a process opens /dev/drm.
 220  *
 221  * \param inode device inode.
 222  * \param filp file pointer.
 223  * \param dev device.
 224  * \return zero on success or a negative number on failure.
 225  *
 226  * Creates and initializes a drm_file structure for the file private data in \p
 227  * filp and add it into the double linked list in \p dev.
 228  */
 229 static int drm_open_helper(struct inode *inode, struct file *filp,
 230                            struct drm_device * dev)
 231 {
 232         int minor_id = iminor(inode);
 233         struct drm_file *priv;
 234         int ret;
 235
 236         if (filp->f_flags & O_EXCL)
 237                 return -EBUSY;  /* No exclusive opens */
 238         if (!drm_cpu_valid())
 239                 return -EINVAL;
 240
 241         DRM_DEBUG("pid = %d, minor = %d\n", task_pid_nr(current), minor_id);
 242
 243         priv = kmalloc(sizeof(*priv), GFP_KERNEL);
 244         if (!priv)
 245                 return -ENOMEM;
 246
 247         memset(priv, 0, sizeof(*priv));
 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         } else {
 304                 /* get a reference to the master */
 305                 priv->master = drm_master_get(priv->minor->master);
 306                 mutex_unlock(&dev->struct_mutex);
 307         }
 308
 309         mutex_lock(&dev->struct_mutex);
 310         list_add(&priv->lhead, &dev->filelist);
 311         mutex_unlock(&dev->struct_mutex);
 312
 313 #ifdef __alpha__
 314         /*
 315          * Default the hose
 316          */
 317         if (!dev->hose) {
 318                 struct pci_dev *pci_dev;
 319                 pci_dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
 320                 if (pci_dev) {
 321                         dev->hose = pci_dev->sysdata;
 322                         pci_dev_put(pci_dev);
 323                 }
 324                 if (!dev->hose) {
 325                         struct pci_bus *b = pci_bus_b(pci_root_buses.next);
 326                         if (b)
 327                                 dev->hose = b->sysdata;
 328                 }
 329         }
 330 #endif
 331
 332         return 0;
 333       out_free:
 334         kfree(priv);
 335         filp->private_data = NULL;
 336         return ret;
 337 }
 338
 339 /** No-op. */
 340 int drm_fasync(int fd, struct file *filp, int on)
 341 {
 342         struct drm_file *priv = filp->private_data;
 343         struct drm_device *dev = priv->minor->dev;
 344
 345         DRM_DEBUG("fd = %d, device = 0x%lx\n", fd,
 346                   (long)old_encode_dev(priv->minor->device));
 347         return fasync_helper(fd, filp, on, &dev->buf_async);
 348 }
 349 EXPORT_SYMBOL(drm_fasync);
 350
 351 /*
 352  * Reclaim locked buffers; note that this may be a bad idea if the current
 353  * context doesn't have the hw lock...
 354  */
 355 static void drm_reclaim_locked_buffers(struct drm_device *dev, struct file *f)
 356 {
 357         struct drm_file *file_priv = f->private_data;
 358
 359         if (drm_i_have_hw_lock(dev, file_priv)) {
 360                 dev->driver->reclaim_buffers_locked(dev, file_priv);
 361         } else {
 362                 unsigned long _end = jiffies + 3 * DRM_HZ;
 363                 int locked = 0;
 364
 365                 drm_idlelock_take(&file_priv->master->lock);
 366
 367                 /*
 368                  * Wait for a while.
 369                  */
 370                 do {
 371                         spin_lock_bh(&file_priv->master->lock.spinlock);
 372                         locked = file_priv->master->lock.idle_has_lock;
 373                         spin_unlock_bh(&file_priv->master->lock.spinlock);
 374                         if (locked)
 375                                 break;
 376                         schedule();
 377                 } while (!time_after_eq(jiffies, _end));
 378
 379                 if (!locked) {
 380                         DRM_ERROR("reclaim_buffers_locked() deadlock. Please rework this\n"
 381                                   "\tdriver to use reclaim_buffers_idlelocked() instead.\n"
 382                                   "\tI will go on reclaiming the buffers anyway.\n");
 383                 }
 384
 385                 dev->driver->reclaim_buffers_locked(dev, file_priv);
 386                 drm_idlelock_release(&file_priv->master->lock);
 387         }
 388 }
 389
 390 static void drm_master_release(struct drm_device *dev, struct file *filp)
 391 {
 392         struct drm_file *file_priv = filp->private_data;
 393
 394         if (dev->driver->reclaim_buffers_locked &&
 395             file_priv->master->lock.hw_lock)
 396                 drm_reclaim_locked_buffers(dev, filp);
 397
 398         if (dev->driver->reclaim_buffers_idlelocked &&
 399             file_priv->master->lock.hw_lock) {
 400                 drm_idlelock_take(&file_priv->master->lock);
 401                 dev->driver->reclaim_buffers_idlelocked(dev, file_priv);
 402                 drm_idlelock_release(&file_priv->master->lock);
 403         }
 404
 405
 406         if (drm_i_have_hw_lock(dev, file_priv)) {
 407                 DRM_DEBUG("File %p released, freeing lock for context %d\n",
 408                           filp, _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
 409                 drm_lock_free(&file_priv->master->lock,
 410                               _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
 411         }
 412
 413         if (drm_core_check_feature(dev, DRIVER_HAVE_DMA) &&
 414             !dev->driver->reclaim_buffers_locked) {
 415                 dev->driver->reclaim_buffers(dev, file_priv);
 416         }
 417 }
 418
 419 static void drm_events_release(struct drm_file *file_priv)
 420 {
 421         struct drm_device *dev = file_priv->minor->dev;
 422         struct drm_pending_event *e, *et;
 423         struct drm_pending_vblank_event *v, *vt;
 424         unsigned long flags;
 425
 426         spin_lock_irqsave(&dev->event_lock, flags);
 427
 428         /* Remove pending flips */
 429         list_for_each_entry_safe(v, vt, &dev->vblank_event_list, base.link)
 430                 if (v->base.file_priv == file_priv) {
 431                         list_del(&v->base.link);
 432                         drm_vblank_put(dev, v->pipe);
 433                         v->base.destroy(&v->base);
 434                 }
 435
 436         /* Remove unconsumed events */
 437         list_for_each_entry_safe(e, et, &file_priv->event_list, link)
 438                 e->destroy(e);
 439
 440         spin_unlock_irqrestore(&dev->event_lock, flags);
 441 }
 442
 443 /**
 444  * Release file.
 445  *
 446  * \param inode device inode
 447  * \param file_priv DRM file private.
 448  * \return zero on success or a negative number on failure.
 449  *
 450  * If the hardware lock is held then free it, and take it again for the kernel
 451  * context since it's necessary to reclaim buffers. Unlink the file private
 452  * data from its list and free it. Decreases the open count and if it reaches
 453  * zero calls drm_lastclose().
 454  */
 455 int drm_release(struct inode *inode, struct file *filp)
 456 {
 457         struct drm_file *file_priv = filp->private_data;
 458         struct drm_device *dev = file_priv->minor->dev;
 459         int retcode = 0;
 460
 461         lock_kernel();
 462
 463         DRM_DEBUG("open_count = %d\n", dev->open_count);
 464
 465         if (dev->driver->preclose)
 466                 dev->driver->preclose(dev, file_priv);
 467
 468         /* ========================================================
 469          * Begin inline drm_release
 470          */
 471
 472         DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
 473                   task_pid_nr(current),
 474                   (long)old_encode_dev(file_priv->minor->device),
 475                   dev->open_count);
 476
 477         /* if the master has gone away we can't do anything with the lock */
 478         if (file_priv->minor->master)
 479                 drm_master_release(dev, filp);
 480
 481         drm_events_release(file_priv);
 482
 483         if (dev->driver->driver_features & DRIVER_GEM)
 484                 drm_gem_release(dev, file_priv);
 485
 486         if (dev->driver->driver_features & DRIVER_MODESET)
 487                 drm_fb_release(file_priv);
 488
 489         mutex_lock(&dev->ctxlist_mutex);
 490         if (!list_empty(&dev->ctxlist)) {
 491                 struct drm_ctx_list *pos, *n;
 492
 493                 list_for_each_entry_safe(pos, n, &dev->ctxlist, head) {
 494                         if (pos->tag == file_priv &&
 495                             pos->handle != DRM_KERNEL_CONTEXT) {
 496                                 if (dev->driver->context_dtor)
 497                                         dev->driver->context_dtor(dev,
 498                                                                   pos->handle);
 499
 500                                 drm_ctxbitmap_free(dev, pos->handle);
 501
 502                                 list_del(&pos->head);
 503                                 kfree(pos);
 504                                 --dev->ctx_count;
 505                         }
 506                 }
 507         }
 508         mutex_unlock(&dev->ctxlist_mutex);
 509
 510         mutex_lock(&dev->struct_mutex);
 511
 512         if (file_priv->is_master) {
 513                 struct drm_master *master = file_priv->master;
 514                 struct drm_file *temp;
 515                 list_for_each_entry(temp, &dev->filelist, lhead) {
 516                         if ((temp->master == file_priv->master) &&
 517                             (temp != file_priv))
 518                                 temp->authenticated = 0;
 519                 }
 520
 521                 /**
 522                  * Since the master is disappearing, so is the
 523                  * possibility to lock.
 524                  */
 525
 526                 if (master->lock.hw_lock) {
 527                         if (dev->sigdata.lock == master->lock.hw_lock)
 528                                 dev->sigdata.lock = NULL;
 529                         master->lock.hw_lock = NULL;
 530                         master->lock.file_priv = NULL;
 531                         wake_up_interruptible_all(&master->lock.lock_queue);
 532                 }
 533
 534                 if (file_priv->minor->master == file_priv->master) {
 535                         /* drop the reference held my the minor */
 536                         drm_master_put(&file_priv->minor->master);
 537                 }
 538         }
 539
 540         /* drop the reference held my the file priv */
 541         drm_master_put(&file_priv->master);
 542         file_priv->is_master = 0;
 543         list_del(&file_priv->lhead);
 544         mutex_unlock(&dev->struct_mutex);
 545
 546         if (dev->driver->postclose)
 547                 dev->driver->postclose(dev, file_priv);
 548         kfree(file_priv);
 549
 550         /* ========================================================
 551          * End inline drm_release
 552          */
 553
 554         atomic_inc(&dev->counts[_DRM_STAT_CLOSES]);
 555         spin_lock(&dev->count_lock);
 556         if (!--dev->open_count) {
 557                 if (atomic_read(&dev->ioctl_count)) {
 558                         DRM_ERROR("Device busy: %d\n",
 559                                   atomic_read(&dev->ioctl_count));
 560                         spin_unlock(&dev->count_lock);
 561                         unlock_kernel();
 562                         return -EBUSY;
 563                 }
 564                 spin_unlock(&dev->count_lock);
 565                 unlock_kernel();
 566                 return drm_lastclose(dev);
 567         }
 568         spin_unlock(&dev->count_lock);
 569
 570         unlock_kernel();
 571
 572         return retcode;
 573 }
 574 EXPORT_SYMBOL(drm_release);
 575
 576 static bool
 577 drm_dequeue_event(struct drm_file *file_priv,
 578                   size_t total, size_t max, struct drm_pending_event **out)
 579 {
 580         struct drm_device *dev = file_priv->minor->dev;
 581         struct drm_pending_event *e;
 582         unsigned long flags;
 583         bool ret = false;
 584
 585         spin_lock_irqsave(&dev->event_lock, flags);
 586
 587         *out = NULL;
 588         if (list_empty(&file_priv->event_list))
 589                 goto out;
 590         e = list_first_entry(&file_priv->event_list,
 591                              struct drm_pending_event, link);
 592         if (e->event->length + total > max)
 593                 goto out;
 594
 595         file_priv->event_space += e->event->length;
 596         list_del(&e->link);
 597         *out = e;
 598         ret = true;
 599
 600 out:
 601         spin_unlock_irqrestore(&dev->event_lock, flags);
 602         return ret;
 603 }
 604
 605 ssize_t drm_read(struct file *filp, char __user *buffer,
 606                  size_t count, loff_t *offset)
 607 {
 608         struct drm_file *file_priv = filp->private_data;
 609         struct drm_pending_event *e;
 610         size_t total;
 611         ssize_t ret;
 612
 613         ret = wait_event_interruptible(file_priv->event_wait,
 614                                        !list_empty(&file_priv->event_list));
 615         if (ret < 0)
 616                 return ret;
 617
 618         total = 0;
 619         while (drm_dequeue_event(file_priv, total, count, &e)) {
 620                 if (copy_to_user(buffer + total,
 621                                  e->event, e->event->length)) {
 622                         total = -EFAULT;
 623                         break;
 624                 }
 625
 626                 total += e->event->length;
 627                 e->destroy(e);
 628         }
 629
 630         return total;
 631 }
 632 EXPORT_SYMBOL(drm_read);
 633
 634 unsigned int drm_poll(struct file *filp, struct poll_table_struct *wait)
 635 {
 636         struct drm_file *file_priv = filp->private_data;
 637         unsigned int mask = 0;
 638
 639         poll_wait(filp, &file_priv->event_wait, wait);
 640
 641         if (!list_empty(&file_priv->event_list))
 642                 mask |= POLLIN | POLLRDNORM;
 643
 644         return mask;
 645 }
 646 EXPORT_SYMBOL(drm_poll);