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