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 <drm/drmP.h>
  38 #include <linux/poll.h>
  39 #include <linux/slab.h>
  40 #include <linux/module.h>
  41
  42 /* from BKL pushdown */
  43 DEFINE_MUTEX(drm_global_mutex);
  44 EXPORT_SYMBOL(drm_global_mutex);
  45
  46 static int drm_open_helper(struct file *filp, struct drm_minor *minor);
  47
  48 static int drm_setup(struct drm_device * dev)
  49 {
  50         int ret;
  51
  52         if (dev->driver->firstopen &&
  53             !drm_core_check_feature(dev, DRIVER_MODESET)) {
  54                 ret = dev->driver->firstopen(dev);
  55                 if (ret != 0)
  56                         return ret;
  57         }
  58
  59         ret = drm_legacy_dma_setup(dev);
  60         if (ret < 0)
  61                 return ret;
  62
  63
  64         DRM_DEBUG("\n");
  65         return 0;
  66 }
  67
  68 /**
  69  * Open file.
  70  *
  71  * \param inode device inode
  72  * \param filp file pointer.
  73  * \return zero on success or a negative number on failure.
  74  *
  75  * Searches the DRM device with the same minor number, calls open_helper(), and
  76  * increments the device open count. If the open count was previous at zero,
  77  * i.e., it's the first that the device is open, then calls setup().
  78  */
  79 int drm_open(struct inode *inode, struct file *filp)
  80 {
  81         struct drm_device *dev;
  82         struct drm_minor *minor;
  83         int retcode;
  84         int need_setup = 0;
  85
  86         minor = drm_minor_acquire(iminor(inode));
  87         if (IS_ERR(minor))
  88                 return PTR_ERR(minor);
  89
  90         dev = minor->dev;
  91         if (!dev->open_count++)
  92                 need_setup = 1;
  93
  94         /* share address_space across all char-devs of a single device */
  95         filp->f_mapping = dev->anon_inode->i_mapping;
  96
  97         retcode = drm_open_helper(filp, minor);
  98         if (retcode)
  99                 goto err_undo;
 100         if (need_setup) {
 101                 retcode = drm_setup(dev);
 102                 if (retcode)
 103                         goto err_undo;
 104         }
 105         return 0;
 106
 107 err_undo:
 108         dev->open_count--;
 109         drm_minor_release(minor);
 110         return retcode;
 111 }
 112 EXPORT_SYMBOL(drm_open);
 113
 114 /**
 115  * File \c open operation.
 116  *
 117  * \param inode device inode.
 118  * \param filp file pointer.
 119  *
 120  * Puts the dev->fops corresponding to the device minor number into
 121  * \p filp, call the \c open method, and restore the file operations.
 122  */
 123 int drm_stub_open(struct inode *inode, struct file *filp)
 124 {
 125         struct drm_device *dev;
 126         struct drm_minor *minor;
 127         int err = -ENODEV;
 128         const struct file_operations *new_fops;
 129
 130         DRM_DEBUG("\n");
 131
 132         mutex_lock(&drm_global_mutex);
 133         minor = drm_minor_acquire(iminor(inode));
 134         if (IS_ERR(minor))
 135                 goto out_unlock;
 136
 137         dev = minor->dev;
 138         new_fops = fops_get(dev->driver->fops);
 139         if (!new_fops)
 140                 goto out_release;
 141
 142         replace_fops(filp, new_fops);
 143         if (filp->f_op->open)
 144                 err = filp->f_op->open(inode, filp);
 145
 146 out_release:
 147         drm_minor_release(minor);
 148 out_unlock:
 149         mutex_unlock(&drm_global_mutex);
 150         return err;
 151 }
 152
 153 /**
 154  * Check whether DRI will run on this CPU.
 155  *
 156  * \return non-zero if the DRI will run on this CPU, or zero otherwise.
 157  */
 158 static int drm_cpu_valid(void)
 159 {
 160 #if defined(__i386__)
 161         if (boot_cpu_data.x86 == 3)
 162                 return 0;       /* No cmpxchg on a 386 */
 163 #endif
 164 #if defined(__sparc__) && !defined(__sparc_v9__)
 165         return 0;               /* No cmpxchg before v9 sparc. */
 166 #endif
 167         return 1;
 168 }
 169
 170 /**
 171  * Called whenever a process opens /dev/drm.
 172  *
 173  * \param filp file pointer.
 174  * \param minor acquired minor-object.
 175  * \return zero on success or a negative number on failure.
 176  *
 177  * Creates and initializes a drm_file structure for the file private data in \p
 178  * filp and add it into the double linked list in \p dev.
 179  */
 180 static int drm_open_helper(struct file *filp, struct drm_minor *minor)
 181 {
 182         struct drm_device *dev = minor->dev;
 183         struct drm_file *priv;
 184         int ret;
 185
 186         if (filp->f_flags & O_EXCL)
 187                 return -EBUSY;  /* No exclusive opens */
 188         if (!drm_cpu_valid())
 189                 return -EINVAL;
 190         if (dev->switch_power_state != DRM_SWITCH_POWER_ON && dev->switch_power_state != DRM_SWITCH_POWER_DYNAMIC_OFF)
 191                 return -EINVAL;
 192
 193         DRM_DEBUG("pid = %d, minor = %d\n", task_pid_nr(current), minor->index);
 194
 195         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 196         if (!priv)
 197                 return -ENOMEM;
 198
 199         filp->private_data = priv;
 200         priv->filp = filp;
 201         priv->uid = current_euid();
 202         priv->pid = get_pid(task_pid(current));
 203         priv->minor = minor;
 204
 205         /* for compatibility root is always authenticated */
 206         priv->always_authenticated = capable(CAP_SYS_ADMIN);
 207         priv->authenticated = priv->always_authenticated;
 208         priv->lock_count = 0;
 209
 210         INIT_LIST_HEAD(&priv->lhead);
 211         INIT_LIST_HEAD(&priv->fbs);
 212         mutex_init(&priv->fbs_lock);
 213         INIT_LIST_HEAD(&priv->event_list);
 214         init_waitqueue_head(&priv->event_wait);
 215         priv->event_space = 4096; /* set aside 4k for event buffer */
 216
 217         if (dev->driver->driver_features & DRIVER_GEM)
 218                 drm_gem_open(dev, priv);
 219
 220         if (drm_core_check_feature(dev, DRIVER_PRIME))
 221                 drm_prime_init_file_private(&priv->prime);
 222
 223         if (dev->driver->open) {
 224                 ret = dev->driver->open(dev, priv);
 225                 if (ret < 0)
 226                         goto out_prime_destroy;
 227         }
 228
 229         /* if there is no current master make this fd it, but do not create
 230          * any master object for render clients */
 231         mutex_lock(&dev->master_mutex);
 232         if (drm_is_primary_client(priv) && !priv->minor->master) {
 233                 /* create a new master */
 234                 priv->minor->master = drm_master_create(priv->minor);
 235                 if (!priv->minor->master) {
 236                         ret = -ENOMEM;
 237                         goto out_close;
 238                 }
 239
 240                 priv->is_master = 1;
 241                 /* take another reference for the copy in the local file priv */
 242                 priv->master = drm_master_get(priv->minor->master);
 243                 priv->authenticated = 1;
 244
 245                 if (dev->driver->master_create) {
 246                         ret = dev->driver->master_create(dev, priv->master);
 247                         if (ret) {
 248                                 /* drop both references if this fails */
 249                                 drm_master_put(&priv->minor->master);
 250                                 drm_master_put(&priv->master);
 251                                 goto out_close;
 252                         }
 253                 }
 254                 if (dev->driver->master_set) {
 255                         ret = dev->driver->master_set(dev, priv, true);
 256                         if (ret) {
 257                                 /* drop both references if this fails */
 258                                 drm_master_put(&priv->minor->master);
 259                                 drm_master_put(&priv->master);
 260                                 goto out_close;
 261                         }
 262                 }
 263         } else if (drm_is_primary_client(priv)) {
 264                 /* get a reference to the master */
 265                 priv->master = drm_master_get(priv->minor->master);
 266         }
 267         mutex_unlock(&dev->master_mutex);
 268
 269         mutex_lock(&dev->struct_mutex);
 270         list_add(&priv->lhead, &dev->filelist);
 271         mutex_unlock(&dev->struct_mutex);
 272
 273 #ifdef __alpha__
 274         /*
 275          * Default the hose
 276          */
 277         if (!dev->hose) {
 278                 struct pci_dev *pci_dev;
 279                 pci_dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
 280                 if (pci_dev) {
 281                         dev->hose = pci_dev->sysdata;
 282                         pci_dev_put(pci_dev);
 283                 }
 284                 if (!dev->hose) {
 285                         struct pci_bus *b = list_entry(pci_root_buses.next,
 286                                 struct pci_bus, node);
 287                         if (b)
 288                                 dev->hose = b->sysdata;
 289                 }
 290         }
 291 #endif
 292
 293         return 0;
 294
 295 out_close:
 296         mutex_unlock(&dev->master_mutex);
 297         if (dev->driver->postclose)
 298                 dev->driver->postclose(dev, priv);
 299 out_prime_destroy:
 300         if (drm_core_check_feature(dev, DRIVER_PRIME))
 301                 drm_prime_destroy_file_private(&priv->prime);
 302         if (dev->driver->driver_features & DRIVER_GEM)
 303                 drm_gem_release(dev, priv);
 304         put_pid(priv->pid);
 305         kfree(priv);
 306         filp->private_data = NULL;
 307         return ret;
 308 }
 309
 310 static void drm_master_release(struct drm_device *dev, struct file *filp)
 311 {
 312         struct drm_file *file_priv = filp->private_data;
 313
 314         if (drm_i_have_hw_lock(dev, file_priv)) {
 315                 DRM_DEBUG("File %p released, freeing lock for context %d\n",
 316                           filp, _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
 317                 drm_lock_free(&file_priv->master->lock,
 318                               _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
 319         }
 320 }
 321
 322 static void drm_events_release(struct drm_file *file_priv)
 323 {
 324         struct drm_device *dev = file_priv->minor->dev;
 325         struct drm_pending_event *e, *et;
 326         struct drm_pending_vblank_event *v, *vt;
 327         unsigned long flags;
 328
 329         spin_lock_irqsave(&dev->event_lock, flags);
 330
 331         /* Remove pending flips */
 332         list_for_each_entry_safe(v, vt, &dev->vblank_event_list, base.link)
 333                 if (v->base.file_priv == file_priv) {
 334                         list_del(&v->base.link);
 335                         drm_vblank_put(dev, v->pipe);
 336                         v->base.destroy(&v->base);
 337                 }
 338
 339         /* Remove unconsumed events */
 340         list_for_each_entry_safe(e, et, &file_priv->event_list, link) {
 341                 list_del(&e->link);
 342                 e->destroy(e);
 343         }
 344
 345         spin_unlock_irqrestore(&dev->event_lock, flags);
 346 }
 347
 348 /**
 349  * drm_legacy_dev_reinit
 350  *
 351  * Reinitializes a legacy/ums drm device in it's lastclose function.
 352  */
 353 static void drm_legacy_dev_reinit(struct drm_device *dev)
 354 {
 355         if (drm_core_check_feature(dev, DRIVER_MODESET))
 356                 return;
 357
 358         dev->sigdata.lock = NULL;
 359
 360         dev->context_flag = 0;
 361         dev->last_context = 0;
 362         dev->if_version = 0;
 363 }
 364
 365 /**
 366  * Take down the DRM device.
 367  *
 368  * \param dev DRM device structure.
 369  *
 370  * Frees every resource in \p dev.
 371  *
 372  * \sa drm_device
 373  */
 374 int drm_lastclose(struct drm_device * dev)
 375 {
 376         struct drm_vma_entry *vma, *vma_temp;
 377
 378         DRM_DEBUG("\n");
 379
 380         if (dev->driver->lastclose)
 381                 dev->driver->lastclose(dev);
 382         DRM_DEBUG("driver lastclose completed\n");
 383
 384         if (dev->irq_enabled && !drm_core_check_feature(dev, DRIVER_MODESET))
 385                 drm_irq_uninstall(dev);
 386
 387         mutex_lock(&dev->struct_mutex);
 388
 389         drm_agp_clear(dev);
 390
 391         drm_legacy_sg_cleanup(dev);
 392
 393         /* Clear vma list (only built for debugging) */
 394         list_for_each_entry_safe(vma, vma_temp, &dev->vmalist, head) {
 395                 list_del(&vma->head);
 396                 kfree(vma);
 397         }
 398
 399         drm_legacy_dma_takedown(dev);
 400
 401         mutex_unlock(&dev->struct_mutex);
 402
 403         drm_legacy_dev_reinit(dev);
 404
 405         DRM_DEBUG("lastclose completed\n");
 406         return 0;
 407 }
 408
 409 /**
 410  * Release file.
 411  *
 412  * \param inode device inode
 413  * \param file_priv DRM file private.
 414  * \return zero on success or a negative number on failure.
 415  *
 416  * If the hardware lock is held then free it, and take it again for the kernel
 417  * context since it's necessary to reclaim buffers. Unlink the file private
 418  * data from its list and free it. Decreases the open count and if it reaches
 419  * zero calls drm_lastclose().
 420  */
 421 int drm_release(struct inode *inode, struct file *filp)
 422 {
 423         struct drm_file *file_priv = filp->private_data;
 424         struct drm_minor *minor = file_priv->minor;
 425         struct drm_device *dev = minor->dev;
 426         int retcode = 0;
 427
 428         mutex_lock(&drm_global_mutex);
 429
 430         DRM_DEBUG("open_count = %d\n", dev->open_count);
 431
 432         if (dev->driver->preclose)
 433                 dev->driver->preclose(dev, file_priv);
 434
 435         /* ========================================================
 436          * Begin inline drm_release
 437          */
 438
 439         DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
 440                   task_pid_nr(current),
 441                   (long)old_encode_dev(file_priv->minor->kdev->devt),
 442                   dev->open_count);
 443
 444         /* Release any auth tokens that might point to this file_priv,
 445            (do that under the drm_global_mutex) */
 446         if (file_priv->magic)
 447                 (void) drm_remove_magic(file_priv->master, file_priv->magic);
 448
 449         /* if the master has gone away we can't do anything with the lock */
 450         if (file_priv->minor->master)
 451                 drm_master_release(dev, filp);
 452
 453         if (drm_core_check_feature(dev, DRIVER_HAVE_DMA))
 454                 drm_core_reclaim_buffers(dev, file_priv);
 455
 456         drm_events_release(file_priv);
 457
 458         if (dev->driver->driver_features & DRIVER_MODESET)
 459                 drm_fb_release(file_priv);
 460
 461         if (dev->driver->driver_features & DRIVER_GEM)
 462                 drm_gem_release(dev, file_priv);
 463
 464         mutex_lock(&dev->ctxlist_mutex);
 465         if (!list_empty(&dev->ctxlist)) {
 466                 struct drm_ctx_list *pos, *n;
 467
 468                 list_for_each_entry_safe(pos, n, &dev->ctxlist, head) {
 469                         if (pos->tag == file_priv &&
 470                             pos->handle != DRM_KERNEL_CONTEXT) {
 471                                 if (dev->driver->context_dtor)
 472                                         dev->driver->context_dtor(dev,
 473                                                                   pos->handle);
 474
 475                                 drm_ctxbitmap_free(dev, pos->handle);
 476
 477                                 list_del(&pos->head);
 478                                 kfree(pos);
 479                         }
 480                 }
 481         }
 482         mutex_unlock(&dev->ctxlist_mutex);
 483
 484         mutex_lock(&dev->master_mutex);
 485
 486         if (file_priv->is_master) {
 487                 struct drm_master *master = file_priv->master;
 488                 struct drm_file *temp;
 489
 490                 mutex_lock(&dev->struct_mutex);
 491                 list_for_each_entry(temp, &dev->filelist, lhead) {
 492                         if ((temp->master == file_priv->master) &&
 493                             (temp != file_priv))
 494                                 temp->authenticated = temp->always_authenticated;
 495                 }
 496
 497                 /**
 498                  * Since the master is disappearing, so is the
 499                  * possibility to lock.
 500                  */
 501
 502                 if (master->lock.hw_lock) {
 503                         if (dev->sigdata.lock == master->lock.hw_lock)
 504                                 dev->sigdata.lock = NULL;
 505                         master->lock.hw_lock = NULL;
 506                         master->lock.file_priv = NULL;
 507                         wake_up_interruptible_all(&master->lock.lock_queue);
 508                 }
 509                 mutex_unlock(&dev->struct_mutex);
 510
 511                 if (file_priv->minor->master == file_priv->master) {
 512                         /* drop the reference held my the minor */
 513                         if (dev->driver->master_drop)
 514                                 dev->driver->master_drop(dev, file_priv, true);
 515                         drm_master_put(&file_priv->minor->master);
 516                 }
 517         }
 518
 519         /* drop the master reference held by the file priv */
 520         if (file_priv->master)
 521                 drm_master_put(&file_priv->master);
 522         file_priv->is_master = 0;
 523         mutex_unlock(&dev->master_mutex);
 524
 525         mutex_lock(&dev->struct_mutex);
 526         list_del(&file_priv->lhead);
 527         mutex_unlock(&dev->struct_mutex);
 528
 529         if (dev->driver->postclose)
 530                 dev->driver->postclose(dev, file_priv);
 531
 532
 533         if (drm_core_check_feature(dev, DRIVER_PRIME))
 534                 drm_prime_destroy_file_private(&file_priv->prime);
 535
 536         put_pid(file_priv->pid);
 537         kfree(file_priv);
 538
 539         /* ========================================================
 540          * End inline drm_release
 541          */
 542
 543         if (!--dev->open_count) {
 544                 retcode = drm_lastclose(dev);
 545                 if (drm_device_is_unplugged(dev))
 546                         drm_put_dev(dev);
 547         }
 548         mutex_unlock(&drm_global_mutex);
 549
 550         drm_minor_release(minor);
 551
 552         return retcode;
 553 }
 554 EXPORT_SYMBOL(drm_release);
 555
 556 static bool
 557 drm_dequeue_event(struct drm_file *file_priv,
 558                   size_t total, size_t max, struct drm_pending_event **out)
 559 {
 560         struct drm_device *dev = file_priv->minor->dev;
 561         struct drm_pending_event *e;
 562         unsigned long flags;
 563         bool ret = false;
 564
 565         spin_lock_irqsave(&dev->event_lock, flags);
 566
 567         *out = NULL;
 568         if (list_empty(&file_priv->event_list))
 569                 goto out;
 570         e = list_first_entry(&file_priv->event_list,
 571                              struct drm_pending_event, link);
 572         if (e->event->length + total > max)
 573                 goto out;
 574
 575         file_priv->event_space += e->event->length;
 576         list_del(&e->link);
 577         *out = e;
 578         ret = true;
 579
 580 out:
 581         spin_unlock_irqrestore(&dev->event_lock, flags);
 582         return ret;
 583 }
 584
 585 ssize_t drm_read(struct file *filp, char __user *buffer,
 586                  size_t count, loff_t *offset)
 587 {
 588         struct drm_file *file_priv = filp->private_data;
 589         struct drm_pending_event *e;
 590         size_t total;
 591         ssize_t ret;
 592
 593         ret = wait_event_interruptible(file_priv->event_wait,
 594                                        !list_empty(&file_priv->event_list));
 595         if (ret < 0)
 596                 return ret;
 597
 598         total = 0;
 599         while (drm_dequeue_event(file_priv, total, count, &e)) {
 600                 if (copy_to_user(buffer + total,
 601                                  e->event, e->event->length)) {
 602                         total = -EFAULT;
 603                         break;
 604                 }
 605
 606                 total += e->event->length;
 607                 e->destroy(e);
 608         }
 609
 610         return total;
 611 }
 612 EXPORT_SYMBOL(drm_read);
 613
 614 unsigned int drm_poll(struct file *filp, struct poll_table_struct *wait)
 615 {
 616         struct drm_file *file_priv = filp->private_data;
 617         unsigned int mask = 0;
 618
 619         poll_wait(filp, &file_priv->event_wait, wait);
 620
 621         if (!list_empty(&file_priv->event_list))
 622                 mask |= POLLIN | POLLRDNORM;
 623
 624         return mask;
 625 }
 626 EXPORT_SYMBOL(drm_poll);