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 = kmalloc(sizeof(*priv), GFP_KERNEL);
 247         if (!priv)
 248                 return -ENOMEM;
 249
 250         memset(priv, 0, sizeof(*priv));
 251         filp->private_data = priv;
 252         priv->filp = filp;
 253         priv->uid = current_euid();
 254         priv->pid = task_pid_nr(current);
 255         priv->minor = idr_find(&drm_minors_idr, minor_id);
 256         priv->ioctl_count = 0;
 257         /* for compatibility root is always authenticated */
 258         priv->authenticated = capable(CAP_SYS_ADMIN);
 259         priv->lock_count = 0;
 260
 261         INIT_LIST_HEAD(&priv->lhead);
 262         INIT_LIST_HEAD(&priv->fbs);
 263         INIT_LIST_HEAD(&priv->event_list);
 264         init_waitqueue_head(&priv->event_wait);
 265         priv->event_space = 4096; /* set aside 4k for event buffer */
 266
 267         if (dev->driver->driver_features & DRIVER_GEM)
 268                 drm_gem_open(dev, priv);
 269
 270         if (dev->driver->open) {
 271                 ret = dev->driver->open(dev, priv);
 272                 if (ret < 0)
 273                         goto out_free;
 274         }
 275
 276
 277         /* if there is no current master make this fd it */
 278         mutex_lock(&dev->struct_mutex);
 279         if (!priv->minor->master) {
 280                 /* create a new master */
 281                 priv->minor->master = drm_master_create(priv->minor);
 282                 if (!priv->minor->master) {
 283                         mutex_unlock(&dev->struct_mutex);
 284                         ret = -ENOMEM;
 285                         goto out_free;
 286                 }
 287
 288                 priv->is_master = 1;
 289                 /* take another reference for the copy in the local file priv */
 290                 priv->master = drm_master_get(priv->minor->master);
 291
 292                 priv->authenticated = 1;
 293
 294                 mutex_unlock(&dev->struct_mutex);
 295                 if (dev->driver->master_create) {
 296                         ret = dev->driver->master_create(dev, priv->master);
 297                         if (ret) {
 298                                 mutex_lock(&dev->struct_mutex);
 299                                 /* drop both references if this fails */
 300                                 drm_master_put(&priv->minor->master);
 301                                 drm_master_put(&priv->master);
 302                                 mutex_unlock(&dev->struct_mutex);
 303                                 goto out_free;
 304                         }
 305                 }
 306                 mutex_lock(&dev->struct_mutex);
 307                 if (dev->driver->master_set) {
 308                         ret = dev->driver->master_set(dev, priv, true);
 309                         if (ret) {
 310                                 /* drop both references if this fails */
 311                                 drm_master_put(&priv->minor->master);
 312                                 drm_master_put(&priv->master);
 313                                 mutex_unlock(&dev->struct_mutex);
 314                                 goto out_free;
 315                         }
 316                 }
 317                 mutex_unlock(&dev->struct_mutex);
 318         } else {
 319                 /* get a reference to the master */
 320                 priv->master = drm_master_get(priv->minor->master);
 321                 mutex_unlock(&dev->struct_mutex);
 322         }
 323
 324         mutex_lock(&dev->struct_mutex);
 325         list_add(&priv->lhead, &dev->filelist);
 326         mutex_unlock(&dev->struct_mutex);
 327
 328 #ifdef __alpha__
 329         /*
 330          * Default the hose
 331          */
 332         if (!dev->hose) {
 333                 struct pci_dev *pci_dev;
 334                 pci_dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
 335                 if (pci_dev) {
 336                         dev->hose = pci_dev->sysdata;
 337                         pci_dev_put(pci_dev);
 338                 }
 339                 if (!dev->hose) {
 340                         struct pci_bus *b = pci_bus_b(pci_root_buses.next);
 341                         if (b)
 342                                 dev->hose = b->sysdata;
 343                 }
 344         }
 345 #endif
 346
 347         return 0;
 348       out_free:
 349         kfree(priv);
 350         filp->private_data = NULL;
 351         return ret;
 352 }
 353
 354 /** No-op. */
 355 int drm_fasync(int fd, struct file *filp, int on)
 356 {
 357         struct drm_file *priv = filp->private_data;
 358         struct drm_device *dev = priv->minor->dev;
 359
 360         DRM_DEBUG("fd = %d, device = 0x%lx\n", fd,
 361                   (long)old_encode_dev(priv->minor->device));
 362         return fasync_helper(fd, filp, on, &dev->buf_async);
 363 }
 364 EXPORT_SYMBOL(drm_fasync);
 365
 366 /*
 367  * Reclaim locked buffers; note that this may be a bad idea if the current
 368  * context doesn't have the hw lock...
 369  */
 370 static void drm_reclaim_locked_buffers(struct drm_device *dev, struct file *f)
 371 {
 372         struct drm_file *file_priv = f->private_data;
 373
 374         if (drm_i_have_hw_lock(dev, file_priv)) {
 375                 dev->driver->reclaim_buffers_locked(dev, file_priv);
 376         } else {
 377                 unsigned long _end = jiffies + 3 * DRM_HZ;
 378                 int locked = 0;
 379
 380                 drm_idlelock_take(&file_priv->master->lock);
 381
 382                 /*
 383                  * Wait for a while.
 384                  */
 385                 do {
 386                         spin_lock_bh(&file_priv->master->lock.spinlock);
 387                         locked = file_priv->master->lock.idle_has_lock;
 388                         spin_unlock_bh(&file_priv->master->lock.spinlock);
 389                         if (locked)
 390                                 break;
 391                         schedule();
 392                 } while (!time_after_eq(jiffies, _end));
 393
 394                 if (!locked) {
 395                         DRM_ERROR("reclaim_buffers_locked() deadlock. Please rework this\n"
 396                                   "\tdriver to use reclaim_buffers_idlelocked() instead.\n"
 397                                   "\tI will go on reclaiming the buffers anyway.\n");
 398                 }
 399
 400                 dev->driver->reclaim_buffers_locked(dev, file_priv);
 401                 drm_idlelock_release(&file_priv->master->lock);
 402         }
 403 }
 404
 405 static void drm_master_release(struct drm_device *dev, struct file *filp)
 406 {
 407         struct drm_file *file_priv = filp->private_data;
 408
 409         if (dev->driver->reclaim_buffers_locked &&
 410             file_priv->master->lock.hw_lock)
 411                 drm_reclaim_locked_buffers(dev, filp);
 412
 413         if (dev->driver->reclaim_buffers_idlelocked &&
 414             file_priv->master->lock.hw_lock) {
 415                 drm_idlelock_take(&file_priv->master->lock);
 416                 dev->driver->reclaim_buffers_idlelocked(dev, file_priv);
 417                 drm_idlelock_release(&file_priv->master->lock);
 418         }
 419
 420
 421         if (drm_i_have_hw_lock(dev, file_priv)) {
 422                 DRM_DEBUG("File %p released, freeing lock for context %d\n",
 423                           filp, _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
 424                 drm_lock_free(&file_priv->master->lock,
 425                               _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
 426         }
 427
 428         if (drm_core_check_feature(dev, DRIVER_HAVE_DMA) &&
 429             !dev->driver->reclaim_buffers_locked) {
 430                 dev->driver->reclaim_buffers(dev, file_priv);
 431         }
 432 }
 433
 434 static void drm_events_release(struct drm_file *file_priv)
 435 {
 436         struct drm_device *dev = file_priv->minor->dev;
 437         struct drm_pending_event *e, *et;
 438         struct drm_pending_vblank_event *v, *vt;
 439         unsigned long flags;
 440
 441         spin_lock_irqsave(&dev->event_lock, flags);
 442
 443         /* Remove pending flips */
 444         list_for_each_entry_safe(v, vt, &dev->vblank_event_list, base.link)
 445                 if (v->base.file_priv == file_priv) {
 446                         list_del(&v->base.link);
 447                         drm_vblank_put(dev, v->pipe);
 448                         v->base.destroy(&v->base);
 449                 }
 450
 451         /* Remove unconsumed events */
 452         list_for_each_entry_safe(e, et, &file_priv->event_list, link)
 453                 e->destroy(e);
 454
 455         spin_unlock_irqrestore(&dev->event_lock, flags);
 456 }
 457
 458 /**
 459  * Release file.
 460  *
 461  * \param inode device inode
 462  * \param file_priv DRM file private.
 463  * \return zero on success or a negative number on failure.
 464  *
 465  * If the hardware lock is held then free it, and take it again for the kernel
 466  * context since it's necessary to reclaim buffers. Unlink the file private
 467  * data from its list and free it. Decreases the open count and if it reaches
 468  * zero calls drm_lastclose().
 469  */
 470 int drm_release(struct inode *inode, struct file *filp)
 471 {
 472         struct drm_file *file_priv = filp->private_data;
 473         struct drm_device *dev = file_priv->minor->dev;
 474         int retcode = 0;
 475
 476         lock_kernel();
 477
 478         DRM_DEBUG("open_count = %d\n", dev->open_count);
 479
 480         if (dev->driver->preclose)
 481                 dev->driver->preclose(dev, file_priv);
 482
 483         /* ========================================================
 484          * Begin inline drm_release
 485          */
 486
 487         DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
 488                   task_pid_nr(current),
 489                   (long)old_encode_dev(file_priv->minor->device),
 490                   dev->open_count);
 491
 492         /* if the master has gone away we can't do anything with the lock */
 493         if (file_priv->minor->master)
 494                 drm_master_release(dev, filp);
 495
 496         drm_events_release(file_priv);
 497
 498         if (dev->driver->driver_features & DRIVER_GEM)
 499                 drm_gem_release(dev, file_priv);
 500
 501         if (dev->driver->driver_features & DRIVER_MODESET)
 502                 drm_fb_release(file_priv);
 503
 504         mutex_lock(&dev->ctxlist_mutex);
 505         if (!list_empty(&dev->ctxlist)) {
 506                 struct drm_ctx_list *pos, *n;
 507
 508                 list_for_each_entry_safe(pos, n, &dev->ctxlist, head) {
 509                         if (pos->tag == file_priv &&
 510                             pos->handle != DRM_KERNEL_CONTEXT) {
 511                                 if (dev->driver->context_dtor)
 512                                         dev->driver->context_dtor(dev,
 513                                                                   pos->handle);
 514
 515                                 drm_ctxbitmap_free(dev, pos->handle);
 516
 517                                 list_del(&pos->head);
 518                                 kfree(pos);
 519                                 --dev->ctx_count;
 520                         }
 521                 }
 522         }
 523         mutex_unlock(&dev->ctxlist_mutex);
 524
 525         mutex_lock(&dev->struct_mutex);
 526
 527         if (file_priv->is_master) {
 528                 struct drm_master *master = file_priv->master;
 529                 struct drm_file *temp;
 530                 list_for_each_entry(temp, &dev->filelist, lhead) {
 531                         if ((temp->master == file_priv->master) &&
 532                             (temp != file_priv))
 533                                 temp->authenticated = 0;
 534                 }
 535
 536                 /**
 537                  * Since the master is disappearing, so is the
 538                  * possibility to lock.
 539                  */
 540
 541                 if (master->lock.hw_lock) {
 542                         if (dev->sigdata.lock == master->lock.hw_lock)
 543                                 dev->sigdata.lock = NULL;
 544                         master->lock.hw_lock = NULL;
 545                         master->lock.file_priv = NULL;
 546                         wake_up_interruptible_all(&master->lock.lock_queue);
 547                 }
 548
 549                 if (file_priv->minor->master == file_priv->master) {
 550                         /* drop the reference held my the minor */
 551                         if (dev->driver->master_drop)
 552                                 dev->driver->master_drop(dev, file_priv, true);
 553                         drm_master_put(&file_priv->minor->master);
 554                 }
 555         }
 556
 557         /* drop the reference held my the file priv */
 558         drm_master_put(&file_priv->master);
 559         file_priv->is_master = 0;
 560         list_del(&file_priv->lhead);
 561         mutex_unlock(&dev->struct_mutex);
 562
 563         if (dev->driver->postclose)
 564                 dev->driver->postclose(dev, file_priv);
 565         kfree(file_priv);
 566
 567         /* ========================================================
 568          * End inline drm_release
 569          */
 570
 571         atomic_inc(&dev->counts[_DRM_STAT_CLOSES]);
 572         spin_lock(&dev->count_lock);
 573         if (!--dev->open_count) {
 574                 if (atomic_read(&dev->ioctl_count)) {
 575                         DRM_ERROR("Device busy: %d\n",
 576                                   atomic_read(&dev->ioctl_count));
 577                         spin_unlock(&dev->count_lock);
 578                         unlock_kernel();
 579                         return -EBUSY;
 580                 }
 581                 spin_unlock(&dev->count_lock);
 582                 unlock_kernel();
 583                 return drm_lastclose(dev);
 584         }
 585         spin_unlock(&dev->count_lock);
 586
 587         unlock_kernel();
 588
 589         return retcode;
 590 }
 591 EXPORT_SYMBOL(drm_release);
 592
 593 static bool
 594 drm_dequeue_event(struct drm_file *file_priv,
 595                   size_t total, size_t max, struct drm_pending_event **out)
 596 {
 597         struct drm_device *dev = file_priv->minor->dev;
 598         struct drm_pending_event *e;
 599         unsigned long flags;
 600         bool ret = false;
 601
 602         spin_lock_irqsave(&dev->event_lock, flags);
 603
 604         *out = NULL;
 605         if (list_empty(&file_priv->event_list))
 606                 goto out;
 607         e = list_first_entry(&file_priv->event_list,
 608                              struct drm_pending_event, link);
 609         if (e->event->length + total > max)
 610                 goto out;
 611
 612         file_priv->event_space += e->event->length;
 613         list_del(&e->link);
 614         *out = e;
 615         ret = true;
 616
 617 out:
 618         spin_unlock_irqrestore(&dev->event_lock, flags);
 619         return ret;
 620 }
 621
 622 ssize_t drm_read(struct file *filp, char __user *buffer,
 623                  size_t count, loff_t *offset)
 624 {
 625         struct drm_file *file_priv = filp->private_data;
 626         struct drm_pending_event *e;
 627         size_t total;
 628         ssize_t ret;
 629
 630         ret = wait_event_interruptible(file_priv->event_wait,
 631                                        !list_empty(&file_priv->event_list));
 632         if (ret < 0)
 633                 return ret;
 634
 635         total = 0;
 636         while (drm_dequeue_event(file_priv, total, count, &e)) {
 637                 if (copy_to_user(buffer + total,
 638                                  e->event, e->event->length)) {
 639                         total = -EFAULT;
 640                         break;
 641                 }
 642
 643                 total += e->event->length;
 644                 e->destroy(e);
 645         }
 646
 647         return total;
 648 }
 649 EXPORT_SYMBOL(drm_read);
 650
 651 unsigned int drm_poll(struct file *filp, struct poll_table_struct *wait)
 652 {
 653         struct drm_file *file_priv = filp->private_data;
 654         unsigned int mask = 0;
 655
 656         poll_wait(filp, &file_priv->event_wait, wait);
 657
 658         if (!list_empty(&file_priv->event_list))
 659                 mask |= POLLIN | POLLRDNORM;
 660
 661         return mask;
 662 }
 663 EXPORT_SYMBOL(drm_poll);