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 #include "drm_internal.h"
  43
  44 /* from BKL pushdown */
  45 DEFINE_MUTEX(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  * drm_new_set_master - Allocate a new master object and become master for the
 130  * associated master realm.
 131  *
 132  * @dev: The associated device.
 133  * @fpriv: File private identifying the client.
 134  *
 135  * This function must be called with dev::struct_mutex held.
 136  * Returns negative error code on failure. Zero on success.
 137  */
 138 int drm_new_set_master(struct drm_device *dev, struct drm_file *fpriv)
 139 {
 140         struct drm_master *old_master;
 141         int ret;
 142
 143         lockdep_assert_held_once(&dev->master_mutex);
 144
 145         /* create a new master */
 146         fpriv->minor->master = drm_master_create(fpriv->minor);
 147         if (!fpriv->minor->master)
 148                 return -ENOMEM;
 149
 150         /* take another reference for the copy in the local file priv */
 151         old_master = fpriv->master;
 152         fpriv->master = drm_master_get(fpriv->minor->master);
 153
 154         if (dev->driver->master_create) {
 155                 ret = dev->driver->master_create(dev, fpriv->master);
 156                 if (ret)
 157                         goto out_err;
 158         }
 159         if (dev->driver->master_set) {
 160                 ret = dev->driver->master_set(dev, fpriv, true);
 161                 if (ret)
 162                         goto out_err;
 163         }
 164
 165         fpriv->is_master = 1;
 166         fpriv->allowed_master = 1;
 167         fpriv->authenticated = 1;
 168         if (old_master)
 169                 drm_master_put(&old_master);
 170
 171         return 0;
 172
 173 out_err:
 174         /* drop both references and restore old master on failure */
 175         drm_master_put(&fpriv->minor->master);
 176         drm_master_put(&fpriv->master);
 177         fpriv->master = old_master;
 178
 179         return ret;
 180 }
 181
 182 /**
 183  * Called whenever a process opens /dev/drm.
 184  *
 185  * \param filp file pointer.
 186  * \param minor acquired minor-object.
 187  * \return zero on success or a negative number on failure.
 188  *
 189  * Creates and initializes a drm_file structure for the file private data in \p
 190  * filp and add it into the double linked list in \p dev.
 191  */
 192 static int drm_open_helper(struct file *filp, struct drm_minor *minor)
 193 {
 194         struct drm_device *dev = minor->dev;
 195         struct drm_file *priv;
 196         int ret;
 197
 198         if (filp->f_flags & O_EXCL)
 199                 return -EBUSY;  /* No exclusive opens */
 200         if (!drm_cpu_valid())
 201                 return -EINVAL;
 202         if (dev->switch_power_state != DRM_SWITCH_POWER_ON && dev->switch_power_state != DRM_SWITCH_POWER_DYNAMIC_OFF)
 203                 return -EINVAL;
 204
 205         DRM_DEBUG("pid = %d, minor = %d\n", task_pid_nr(current), minor->index);
 206
 207         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 208         if (!priv)
 209                 return -ENOMEM;
 210
 211         filp->private_data = priv;
 212         priv->filp = filp;
 213         priv->uid = current_euid();
 214         priv->pid = get_pid(task_pid(current));
 215         priv->minor = minor;
 216
 217         /* for compatibility root is always authenticated */
 218         priv->authenticated = capable(CAP_SYS_ADMIN);
 219         priv->lock_count = 0;
 220
 221         INIT_LIST_HEAD(&priv->lhead);
 222         INIT_LIST_HEAD(&priv->fbs);
 223         mutex_init(&priv->fbs_lock);
 224         INIT_LIST_HEAD(&priv->blobs);
 225         INIT_LIST_HEAD(&priv->event_list);
 226         init_waitqueue_head(&priv->event_wait);
 227         priv->event_space = 4096; /* set aside 4k for event buffer */
 228
 229         mutex_init(&priv->event_read_lock);
 230
 231         if (drm_core_check_feature(dev, DRIVER_GEM))
 232                 drm_gem_open(dev, priv);
 233
 234         if (drm_core_check_feature(dev, DRIVER_PRIME))
 235                 drm_prime_init_file_private(&priv->prime);
 236
 237         if (dev->driver->open) {
 238                 ret = dev->driver->open(dev, priv);
 239                 if (ret < 0)
 240                         goto out_prime_destroy;
 241         }
 242
 243         /* if there is no current master make this fd it, but do not create
 244          * any master object for render clients */
 245         mutex_lock(&dev->master_mutex);
 246         if (drm_is_primary_client(priv) && !priv->minor->master) {
 247                 /* create a new master */
 248                 ret = drm_new_set_master(dev, priv);
 249                 if (ret)
 250                         goto out_close;
 251         } else if (drm_is_primary_client(priv)) {
 252                 /* get a reference to the master */
 253                 priv->master = drm_master_get(priv->minor->master);
 254         }
 255         mutex_unlock(&dev->master_mutex);
 256
 257         mutex_lock(&dev->struct_mutex);
 258         list_add(&priv->lhead, &dev->filelist);
 259         mutex_unlock(&dev->struct_mutex);
 260
 261 #ifdef __alpha__
 262         /*
 263          * Default the hose
 264          */
 265         if (!dev->hose) {
 266                 struct pci_dev *pci_dev;
 267                 pci_dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
 268                 if (pci_dev) {
 269                         dev->hose = pci_dev->sysdata;
 270                         pci_dev_put(pci_dev);
 271                 }
 272                 if (!dev->hose) {
 273                         struct pci_bus *b = list_entry(pci_root_buses.next,
 274                                 struct pci_bus, node);
 275                         if (b)
 276                                 dev->hose = b->sysdata;
 277                 }
 278         }
 279 #endif
 280
 281         return 0;
 282
 283 out_close:
 284         mutex_unlock(&dev->master_mutex);
 285         if (dev->driver->postclose)
 286                 dev->driver->postclose(dev, priv);
 287 out_prime_destroy:
 288         if (drm_core_check_feature(dev, DRIVER_PRIME))
 289                 drm_prime_destroy_file_private(&priv->prime);
 290         if (drm_core_check_feature(dev, DRIVER_GEM))
 291                 drm_gem_release(dev, priv);
 292         put_pid(priv->pid);
 293         kfree(priv);
 294         filp->private_data = NULL;
 295         return ret;
 296 }
 297
 298 static void drm_master_release(struct drm_device *dev, struct file *filp)
 299 {
 300         struct drm_file *file_priv = filp->private_data;
 301
 302         if (drm_legacy_i_have_hw_lock(dev, file_priv)) {
 303                 DRM_DEBUG("File %p released, freeing lock for context %d\n",
 304                           filp, _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
 305                 drm_legacy_lock_free(&file_priv->master->lock,
 306                                      _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
 307         }
 308 }
 309
 310 static void drm_events_release(struct drm_file *file_priv)
 311 {
 312         struct drm_device *dev = file_priv->minor->dev;
 313         struct drm_pending_event *e, *et;
 314         struct drm_pending_vblank_event *v, *vt;
 315         unsigned long flags;
 316
 317         spin_lock_irqsave(&dev->event_lock, flags);
 318
 319         /* Remove pending flips */
 320         list_for_each_entry_safe(v, vt, &dev->vblank_event_list, base.link)
 321                 if (v->base.file_priv == file_priv) {
 322                         list_del(&v->base.link);
 323                         drm_vblank_put(dev, v->pipe);
 324                         v->base.destroy(&v->base);
 325                 }
 326
 327         /* Remove unconsumed events */
 328         list_for_each_entry_safe(e, et, &file_priv->event_list, link) {
 329                 list_del(&e->link);
 330                 e->destroy(e);
 331         }
 332
 333         spin_unlock_irqrestore(&dev->event_lock, flags);
 334 }
 335
 336 /**
 337  * drm_legacy_dev_reinit
 338  *
 339  * Reinitializes a legacy/ums drm device in it's lastclose function.
 340  */
 341 static void drm_legacy_dev_reinit(struct drm_device *dev)
 342 {
 343         if (drm_core_check_feature(dev, DRIVER_MODESET))
 344                 return;
 345
 346         dev->sigdata.lock = NULL;
 347
 348         dev->context_flag = 0;
 349         dev->last_context = 0;
 350         dev->if_version = 0;
 351 }
 352
 353 /**
 354  * Take down the DRM device.
 355  *
 356  * \param dev DRM device structure.
 357  *
 358  * Frees every resource in \p dev.
 359  *
 360  * \sa drm_device
 361  */
 362 int drm_lastclose(struct drm_device * dev)
 363 {
 364         DRM_DEBUG("\n");
 365
 366         if (dev->driver->lastclose)
 367                 dev->driver->lastclose(dev);
 368         DRM_DEBUG("driver lastclose completed\n");
 369
 370         if (dev->irq_enabled && !drm_core_check_feature(dev, DRIVER_MODESET))
 371                 drm_irq_uninstall(dev);
 372
 373         mutex_lock(&dev->struct_mutex);
 374
 375         drm_agp_clear(dev);
 376
 377         drm_legacy_sg_cleanup(dev);
 378         drm_legacy_vma_flush(dev);
 379         drm_legacy_dma_takedown(dev);
 380
 381         mutex_unlock(&dev->struct_mutex);
 382
 383         drm_legacy_dev_reinit(dev);
 384
 385         DRM_DEBUG("lastclose completed\n");
 386         return 0;
 387 }
 388
 389 /**
 390  * Release file.
 391  *
 392  * \param inode device inode
 393  * \param file_priv DRM file private.
 394  * \return zero on success or a negative number on failure.
 395  *
 396  * If the hardware lock is held then free it, and take it again for the kernel
 397  * context since it's necessary to reclaim buffers. Unlink the file private
 398  * data from its list and free it. Decreases the open count and if it reaches
 399  * zero calls drm_lastclose().
 400  */
 401 int drm_release(struct inode *inode, struct file *filp)
 402 {
 403         struct drm_file *file_priv = filp->private_data;
 404         struct drm_minor *minor = file_priv->minor;
 405         struct drm_device *dev = minor->dev;
 406         int retcode = 0;
 407
 408         mutex_lock(&drm_global_mutex);
 409
 410         DRM_DEBUG("open_count = %d\n", dev->open_count);
 411
 412         mutex_lock(&dev->struct_mutex);
 413         list_del(&file_priv->lhead);
 414         if (file_priv->magic)
 415                 idr_remove(&file_priv->master->magic_map, file_priv->magic);
 416         mutex_unlock(&dev->struct_mutex);
 417
 418         if (dev->driver->preclose)
 419                 dev->driver->preclose(dev, file_priv);
 420
 421         /* ========================================================
 422          * Begin inline drm_release
 423          */
 424
 425         DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
 426                   task_pid_nr(current),
 427                   (long)old_encode_dev(file_priv->minor->kdev->devt),
 428                   dev->open_count);
 429
 430         /* if the master has gone away we can't do anything with the lock */
 431         if (file_priv->minor->master)
 432                 drm_master_release(dev, filp);
 433
 434         if (drm_core_check_feature(dev, DRIVER_HAVE_DMA))
 435                 drm_legacy_reclaim_buffers(dev, file_priv);
 436
 437         drm_events_release(file_priv);
 438
 439         if (drm_core_check_feature(dev, DRIVER_MODESET)) {
 440                 drm_fb_release(file_priv);
 441                 drm_property_destroy_user_blobs(dev, file_priv);
 442         }
 443
 444         if (drm_core_check_feature(dev, DRIVER_GEM))
 445                 drm_gem_release(dev, file_priv);
 446
 447         drm_legacy_ctxbitmap_flush(dev, file_priv);
 448
 449         mutex_lock(&dev->master_mutex);
 450
 451         if (file_priv->is_master) {
 452                 struct drm_master *master = file_priv->master;
 453
 454                 /**
 455                  * Since the master is disappearing, so is the
 456                  * possibility to lock.
 457                  */
 458                 mutex_lock(&dev->struct_mutex);
 459                 if (master->lock.hw_lock) {
 460                         if (dev->sigdata.lock == master->lock.hw_lock)
 461                                 dev->sigdata.lock = NULL;
 462                         master->lock.hw_lock = NULL;
 463                         master->lock.file_priv = NULL;
 464                         wake_up_interruptible_all(&master->lock.lock_queue);
 465                 }
 466                 mutex_unlock(&dev->struct_mutex);
 467
 468                 if (file_priv->minor->master == file_priv->master) {
 469                         /* drop the reference held my the minor */
 470                         if (dev->driver->master_drop)
 471                                 dev->driver->master_drop(dev, file_priv, true);
 472                         drm_master_put(&file_priv->minor->master);
 473                 }
 474         }
 475
 476         /* drop the master reference held by the file priv */
 477         if (file_priv->master)
 478                 drm_master_put(&file_priv->master);
 479         file_priv->is_master = 0;
 480         mutex_unlock(&dev->master_mutex);
 481
 482         if (dev->driver->postclose)
 483                 dev->driver->postclose(dev, file_priv);
 484
 485
 486         if (drm_core_check_feature(dev, DRIVER_PRIME))
 487                 drm_prime_destroy_file_private(&file_priv->prime);
 488
 489         WARN_ON(!list_empty(&file_priv->event_list));
 490
 491         put_pid(file_priv->pid);
 492         kfree(file_priv);
 493
 494         /* ========================================================
 495          * End inline drm_release
 496          */
 497
 498         if (!--dev->open_count) {
 499                 retcode = drm_lastclose(dev);
 500                 if (drm_device_is_unplugged(dev))
 501                         drm_put_dev(dev);
 502         }
 503         mutex_unlock(&drm_global_mutex);
 504
 505         drm_minor_release(minor);
 506
 507         return retcode;
 508 }
 509 EXPORT_SYMBOL(drm_release);
 510
 511 ssize_t drm_read(struct file *filp, char __user *buffer,
 512                  size_t count, loff_t *offset)
 513 {
 514         struct drm_file *file_priv = filp->private_data;
 515         struct drm_device *dev = file_priv->minor->dev;
 516         ssize_t ret;
 517
 518         if (!access_ok(VERIFY_WRITE, buffer, count))
 519                 return -EFAULT;
 520
 521         ret = mutex_lock_interruptible(&file_priv->event_read_lock);
 522         if (ret)
 523                 return ret;
 524
 525         for (;;) {
 526                 struct drm_pending_event *e = NULL;
 527
 528                 spin_lock_irq(&dev->event_lock);
 529                 if (!list_empty(&file_priv->event_list)) {
 530                         e = list_first_entry(&file_priv->event_list,
 531                                         struct drm_pending_event, link);
 532                         file_priv->event_space += e->event->length;
 533                         list_del(&e->link);
 534                 }
 535                 spin_unlock_irq(&dev->event_lock);
 536
 537                 if (e == NULL) {
 538                         if (ret)
 539                                 break;
 540
 541                         if (filp->f_flags & O_NONBLOCK) {
 542                                 ret = -EAGAIN;
 543                                 break;
 544                         }
 545
 546                         mutex_unlock(&file_priv->event_read_lock);
 547                         ret = wait_event_interruptible(file_priv->event_wait,
 548                                                        !list_empty(&file_priv->event_list));
 549                         if (ret >= 0)
 550                                 ret = mutex_lock_interruptible(&file_priv->event_read_lock);
 551                         if (ret)
 552                                 return ret;
 553                 } else {
 554                         unsigned length = e->event->length;
 555
 556                         if (length > count - ret) {
 557 put_back_event:
 558                                 spin_lock_irq(&dev->event_lock);
 559                                 file_priv->event_space -= length;
 560                                 list_add(&e->link, &file_priv->event_list);
 561                                 spin_unlock_irq(&dev->event_lock);
 562                                 break;
 563                         }
 564
 565                         if (copy_to_user(buffer + ret, e->event, length)) {
 566                                 if (ret == 0)
 567                                         ret = -EFAULT;
 568                                 goto put_back_event;
 569                         }
 570
 571                         ret += length;
 572                         e->destroy(e);
 573                 }
 574         }
 575         mutex_unlock(&file_priv->event_read_lock);
 576
 577         return ret;
 578 }
 579 EXPORT_SYMBOL(drm_read);
 580
 581 unsigned int drm_poll(struct file *filp, struct poll_table_struct *wait)
 582 {
 583         struct drm_file *file_priv = filp->private_data;
 584         unsigned int mask = 0;
 585
 586         poll_wait(filp, &file_priv->event_wait, wait);
 587
 588         if (!list_empty(&file_priv->event_list))
 589                 mask |= POLLIN | POLLRDNORM;
 590
 591         return mask;
 592 }
 593 EXPORT_SYMBOL(drm_poll);