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 /* from BKL pushdown: note that nothing else serializes idr_find() */
  43 DEFINE_MUTEX(drm_global_mutex);
  44 EXPORT_SYMBOL(drm_global_mutex);
  45
  46 static int drm_open_helper(struct inode *inode, struct file *filp,
  47                            struct drm_device * dev);
  48
  49 static int drm_setup(struct drm_device * dev)
  50 {
  51         int i;
  52         int ret;
  53
  54         if (dev->driver->firstopen) {
  55                 ret = dev->driver->firstopen(dev);
  56                 if (ret != 0)
  57                         return ret;
  58         }
  59
  60         atomic_set(&dev->ioctl_count, 0);
  61         atomic_set(&dev->vma_count, 0);
  62
  63         if (drm_core_check_feature(dev, DRIVER_HAVE_DMA) &&
  64             !drm_core_check_feature(dev, DRIVER_MODESET)) {
  65                 dev->buf_use = 0;
  66                 atomic_set(&dev->buf_alloc, 0);
  67
  68                 i = drm_dma_setup(dev);
  69                 if (i < 0)
  70                         return i;
  71         }
  72
  73         for (i = 0; i < ARRAY_SIZE(dev->counts); i++)
  74                 atomic_set(&dev->counts[i], 0);
  75
  76         dev->sigdata.lock = NULL;
  77
  78         dev->queue_count = 0;
  79         dev->queue_reserved = 0;
  80         dev->queue_slots = 0;
  81         dev->queuelist = NULL;
  82         dev->context_flag = 0;
  83         dev->interrupt_flag = 0;
  84         dev->dma_flag = 0;
  85         dev->last_context = 0;
  86         dev->last_switch = 0;
  87         dev->last_checked = 0;
  88         init_waitqueue_head(&dev->context_wait);
  89         dev->if_version = 0;
  90
  91         dev->ctx_start = 0;
  92         dev->lck_start = 0;
  93
  94         dev->buf_async = NULL;
  95         init_waitqueue_head(&dev->buf_readers);
  96         init_waitqueue_head(&dev->buf_writers);
  97
  98         DRM_DEBUG("\n");
  99
 100         /*
 101          * The kernel's context could be created here, but is now created
 102          * in drm_dma_enqueue.  This is more resource-efficient for
 103          * hardware that does not do DMA, but may mean that
 104          * drm_select_queue fails between the time the interrupt is
 105          * initialized and the time the queues are initialized.
 106          */
 107
 108         return 0;
 109 }
 110
 111 /**
 112  * Open file.
 113  *
 114  * \param inode device inode
 115  * \param filp file pointer.
 116  * \return zero on success or a negative number on failure.
 117  *
 118  * Searches the DRM device with the same minor number, calls open_helper(), and
 119  * increments the device open count. If the open count was previous at zero,
 120  * i.e., it's the first that the device is open, then calls setup().
 121  */
 122 int drm_open(struct inode *inode, struct file *filp)
 123 {
 124         struct drm_device *dev = NULL;
 125         int minor_id = iminor(inode);
 126         struct drm_minor *minor;
 127         int retcode = 0;
 128
 129         minor = idr_find(&drm_minors_idr, minor_id);
 130         if (!minor)
 131                 return -ENODEV;
 132
 133         if (!(dev = minor->dev))
 134                 return -ENODEV;
 135
 136         retcode = drm_open_helper(inode, filp, dev);
 137         if (!retcode) {
 138                 atomic_inc(&dev->counts[_DRM_STAT_OPENS]);
 139                 if (!dev->open_count++)
 140                         retcode = drm_setup(dev);
 141         }
 142         if (!retcode) {
 143                 mutex_lock(&dev->struct_mutex);
 144                 if (minor->type == DRM_MINOR_LEGACY) {
 145                         if (dev->dev_mapping == NULL)
 146                                 dev->dev_mapping = inode->i_mapping;
 147                         else if (dev->dev_mapping != inode->i_mapping)
 148                                 retcode = -ENODEV;
 149                 }
 150                 mutex_unlock(&dev->struct_mutex);
 151         }
 152
 153         return retcode;
 154 }
 155 EXPORT_SYMBOL(drm_open);
 156
 157 /**
 158  * File \c open operation.
 159  *
 160  * \param inode device inode.
 161  * \param filp file pointer.
 162  *
 163  * Puts the dev->fops corresponding to the device minor number into
 164  * \p filp, call the \c open method, and restore the file operations.
 165  */
 166 int drm_stub_open(struct inode *inode, struct file *filp)
 167 {
 168         struct drm_device *dev = NULL;
 169         struct drm_minor *minor;
 170         int minor_id = iminor(inode);
 171         int err = -ENODEV;
 172         const struct file_operations *old_fops;
 173
 174         DRM_DEBUG("\n");
 175
 176         mutex_lock(&drm_global_mutex);
 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         mutex_unlock(&drm_global_mutex);
 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 = kzalloc(sizeof(*priv), GFP_KERNEL);
 244         if (!priv)
 245                 return -ENOMEM;
 246
 247         filp->private_data = priv;
 248         priv->filp = filp;
 249         priv->uid = current_euid();
 250         priv->pid = task_pid_nr(current);
 251         priv->minor = idr_find(&drm_minors_idr, minor_id);
 252         priv->ioctl_count = 0;
 253         /* for compatibility root is always authenticated */
 254         priv->authenticated = capable(CAP_SYS_ADMIN);
 255         priv->lock_count = 0;
 256
 257         INIT_LIST_HEAD(&priv->lhead);
 258         INIT_LIST_HEAD(&priv->fbs);
 259         INIT_LIST_HEAD(&priv->event_list);
 260         init_waitqueue_head(&priv->event_wait);
 261         priv->event_space = 4096; /* set aside 4k for event buffer */
 262
 263         if (dev->driver->driver_features & DRIVER_GEM)
 264                 drm_gem_open(dev, priv);
 265
 266         if (dev->driver->open) {
 267                 ret = dev->driver->open(dev, priv);
 268                 if (ret < 0)
 269                         goto out_free;
 270         }
 271
 272
 273         /* if there is no current master make this fd it */
 274         mutex_lock(&dev->struct_mutex);
 275         if (!priv->minor->master) {
 276                 /* create a new master */
 277                 priv->minor->master = drm_master_create(priv->minor);
 278                 if (!priv->minor->master) {
 279                         mutex_unlock(&dev->struct_mutex);
 280                         ret = -ENOMEM;
 281                         goto out_free;
 282                 }
 283
 284                 priv->is_master = 1;
 285                 /* take another reference for the copy in the local file priv */
 286                 priv->master = drm_master_get(priv->minor->master);
 287
 288                 priv->authenticated = 1;
 289
 290                 mutex_unlock(&dev->struct_mutex);
 291                 if (dev->driver->master_create) {
 292                         ret = dev->driver->master_create(dev, priv->master);
 293                         if (ret) {
 294                                 mutex_lock(&dev->struct_mutex);
 295                                 /* drop both references if this fails */
 296                                 drm_master_put(&priv->minor->master);
 297                                 drm_master_put(&priv->master);
 298                                 mutex_unlock(&dev->struct_mutex);
 299                                 goto out_free;
 300                         }
 301                 }
 302                 mutex_lock(&dev->struct_mutex);
 303                 if (dev->driver->master_set) {
 304                         ret = dev->driver->master_set(dev, priv, true);
 305                         if (ret) {
 306                                 /* drop both references if this fails */
 307                                 drm_master_put(&priv->minor->master);
 308                                 drm_master_put(&priv->master);
 309                                 mutex_unlock(&dev->struct_mutex);
 310                                 goto out_free;
 311                         }
 312                 }
 313                 mutex_unlock(&dev->struct_mutex);
 314         } else {
 315                 /* get a reference to the master */
 316                 priv->master = drm_master_get(priv->minor->master);
 317                 mutex_unlock(&dev->struct_mutex);
 318         }
 319
 320         mutex_lock(&dev->struct_mutex);
 321         list_add(&priv->lhead, &dev->filelist);
 322         mutex_unlock(&dev->struct_mutex);
 323
 324 #ifdef __alpha__
 325         /*
 326          * Default the hose
 327          */
 328         if (!dev->hose) {
 329                 struct pci_dev *pci_dev;
 330                 pci_dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
 331                 if (pci_dev) {
 332                         dev->hose = pci_dev->sysdata;
 333                         pci_dev_put(pci_dev);
 334                 }
 335                 if (!dev->hose) {
 336                         struct pci_bus *b = pci_bus_b(pci_root_buses.next);
 337                         if (b)
 338                                 dev->hose = b->sysdata;
 339                 }
 340         }
 341 #endif
 342
 343         return 0;
 344       out_free:
 345         kfree(priv);
 346         filp->private_data = NULL;
 347         return ret;
 348 }
 349
 350 /** No-op. */
 351 int drm_fasync(int fd, struct file *filp, int on)
 352 {
 353         struct drm_file *priv = filp->private_data;
 354         struct drm_device *dev = priv->minor->dev;
 355
 356         DRM_DEBUG("fd = %d, device = 0x%lx\n", fd,
 357                   (long)old_encode_dev(priv->minor->device));
 358         return fasync_helper(fd, filp, on, &dev->buf_async);
 359 }
 360 EXPORT_SYMBOL(drm_fasync);
 361
 362 /*
 363  * Reclaim locked buffers; note that this may be a bad idea if the current
 364  * context doesn't have the hw lock...
 365  */
 366 static void drm_reclaim_locked_buffers(struct drm_device *dev, struct file *f)
 367 {
 368         struct drm_file *file_priv = f->private_data;
 369
 370         if (drm_i_have_hw_lock(dev, file_priv)) {
 371                 dev->driver->reclaim_buffers_locked(dev, file_priv);
 372         } else {
 373                 unsigned long _end = jiffies + 3 * DRM_HZ;
 374                 int locked = 0;
 375
 376                 drm_idlelock_take(&file_priv->master->lock);
 377
 378                 /*
 379                  * Wait for a while.
 380                  */
 381                 do {
 382                         spin_lock_bh(&file_priv->master->lock.spinlock);
 383                         locked = file_priv->master->lock.idle_has_lock;
 384                         spin_unlock_bh(&file_priv->master->lock.spinlock);
 385                         if (locked)
 386                                 break;
 387                         schedule();
 388                 } while (!time_after_eq(jiffies, _end));
 389
 390                 if (!locked) {
 391                         DRM_ERROR("reclaim_buffers_locked() deadlock. Please rework this\n"
 392                                   "\tdriver to use reclaim_buffers_idlelocked() instead.\n"
 393                                   "\tI will go on reclaiming the buffers anyway.\n");
 394                 }
 395
 396                 dev->driver->reclaim_buffers_locked(dev, file_priv);
 397                 drm_idlelock_release(&file_priv->master->lock);
 398         }
 399 }
 400
 401 static void drm_master_release(struct drm_device *dev, struct file *filp)
 402 {
 403         struct drm_file *file_priv = filp->private_data;
 404
 405         if (dev->driver->reclaim_buffers_locked &&
 406             file_priv->master->lock.hw_lock)
 407                 drm_reclaim_locked_buffers(dev, filp);
 408
 409         if (dev->driver->reclaim_buffers_idlelocked &&
 410             file_priv->master->lock.hw_lock) {
 411                 drm_idlelock_take(&file_priv->master->lock);
 412                 dev->driver->reclaim_buffers_idlelocked(dev, file_priv);
 413                 drm_idlelock_release(&file_priv->master->lock);
 414         }
 415
 416
 417         if (drm_i_have_hw_lock(dev, file_priv)) {
 418                 DRM_DEBUG("File %p released, freeing lock for context %d\n",
 419                           filp, _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
 420                 drm_lock_free(&file_priv->master->lock,
 421                               _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
 422         }
 423
 424         if (drm_core_check_feature(dev, DRIVER_HAVE_DMA) &&
 425             !dev->driver->reclaim_buffers_locked) {
 426                 dev->driver->reclaim_buffers(dev, file_priv);
 427         }
 428 }
 429
 430 static void drm_events_release(struct drm_file *file_priv)
 431 {
 432         struct drm_device *dev = file_priv->minor->dev;
 433         struct drm_pending_event *e, *et;
 434         struct drm_pending_vblank_event *v, *vt;
 435         unsigned long flags;
 436
 437         spin_lock_irqsave(&dev->event_lock, flags);
 438
 439         /* Remove pending flips */
 440         list_for_each_entry_safe(v, vt, &dev->vblank_event_list, base.link)
 441                 if (v->base.file_priv == file_priv) {
 442                         list_del(&v->base.link);
 443                         drm_vblank_put(dev, v->pipe);
 444                         v->base.destroy(&v->base);
 445                 }
 446
 447         /* Remove unconsumed events */
 448         list_for_each_entry_safe(e, et, &file_priv->event_list, link)
 449                 e->destroy(e);
 450
 451         spin_unlock_irqrestore(&dev->event_lock, flags);
 452 }
 453
 454 /**
 455  * Release file.
 456  *
 457  * \param inode device inode
 458  * \param file_priv DRM file private.
 459  * \return zero on success or a negative number on failure.
 460  *
 461  * If the hardware lock is held then free it, and take it again for the kernel
 462  * context since it's necessary to reclaim buffers. Unlink the file private
 463  * data from its list and free it. Decreases the open count and if it reaches
 464  * zero calls drm_lastclose().
 465  */
 466 int drm_release(struct inode *inode, struct file *filp)
 467 {
 468         struct drm_file *file_priv = filp->private_data;
 469         struct drm_device *dev = file_priv->minor->dev;
 470         int retcode = 0;
 471
 472         mutex_lock(&drm_global_mutex);
 473
 474         DRM_DEBUG("open_count = %d\n", dev->open_count);
 475
 476         if (dev->driver->preclose)
 477                 dev->driver->preclose(dev, file_priv);
 478
 479         /* ========================================================
 480          * Begin inline drm_release
 481          */
 482
 483         DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
 484                   task_pid_nr(current),
 485                   (long)old_encode_dev(file_priv->minor->device),
 486                   dev->open_count);
 487
 488         /* if the master has gone away we can't do anything with the lock */
 489         if (file_priv->minor->master)
 490                 drm_master_release(dev, filp);
 491
 492         drm_events_release(file_priv);
 493
 494         if (dev->driver->driver_features & DRIVER_GEM)
 495                 drm_gem_release(dev, file_priv);
 496
 497         if (dev->driver->driver_features & DRIVER_MODESET)
 498                 drm_fb_release(file_priv);
 499
 500         mutex_lock(&dev->ctxlist_mutex);
 501         if (!list_empty(&dev->ctxlist)) {
 502                 struct drm_ctx_list *pos, *n;
 503
 504                 list_for_each_entry_safe(pos, n, &dev->ctxlist, head) {
 505                         if (pos->tag == file_priv &&
 506                             pos->handle != DRM_KERNEL_CONTEXT) {
 507                                 if (dev->driver->context_dtor)
 508                                         dev->driver->context_dtor(dev,
 509                                                                   pos->handle);
 510
 511                                 drm_ctxbitmap_free(dev, pos->handle);
 512
 513                                 list_del(&pos->head);
 514                                 kfree(pos);
 515                                 --dev->ctx_count;
 516                         }
 517                 }
 518         }
 519         mutex_unlock(&dev->ctxlist_mutex);
 520
 521         mutex_lock(&dev->struct_mutex);
 522
 523         if (file_priv->is_master) {
 524                 struct drm_master *master = file_priv->master;
 525                 struct drm_file *temp;
 526                 list_for_each_entry(temp, &dev->filelist, lhead) {
 527                         if ((temp->master == file_priv->master) &&
 528                             (temp != file_priv))
 529                                 temp->authenticated = 0;
 530                 }
 531
 532                 /**
 533                  * Since the master is disappearing, so is the
 534                  * possibility to lock.
 535                  */
 536
 537                 if (master->lock.hw_lock) {
 538                         if (dev->sigdata.lock == master->lock.hw_lock)
 539                                 dev->sigdata.lock = NULL;
 540                         master->lock.hw_lock = NULL;
 541                         master->lock.file_priv = NULL;
 542                         wake_up_interruptible_all(&master->lock.lock_queue);
 543                 }
 544
 545                 if (file_priv->minor->master == file_priv->master) {
 546                         /* drop the reference held my the minor */
 547                         if (dev->driver->master_drop)
 548                                 dev->driver->master_drop(dev, file_priv, true);
 549                         drm_master_put(&file_priv->minor->master);
 550                 }
 551         }
 552
 553         /* drop the reference held my the file priv */
 554         drm_master_put(&file_priv->master);
 555         file_priv->is_master = 0;
 556         list_del(&file_priv->lhead);
 557         mutex_unlock(&dev->struct_mutex);
 558
 559         if (dev->driver->postclose)
 560                 dev->driver->postclose(dev, file_priv);
 561         kfree(file_priv);
 562
 563         /* ========================================================
 564          * End inline drm_release
 565          */
 566
 567         atomic_inc(&dev->counts[_DRM_STAT_CLOSES]);
 568         if (!--dev->open_count) {
 569                 if (atomic_read(&dev->ioctl_count)) {
 570                         DRM_ERROR("Device busy: %d\n",
 571                                   atomic_read(&dev->ioctl_count));
 572                         retcode = -EBUSY;
 573                 } else
 574                         retcode = drm_lastclose(dev);
 575         }
 576         mutex_unlock(&drm_global_mutex);
 577
 578         return retcode;
 579 }
 580 EXPORT_SYMBOL(drm_release);
 581
 582 static bool
 583 drm_dequeue_event(struct drm_file *file_priv,
 584                   size_t total, size_t max, struct drm_pending_event **out)
 585 {
 586         struct drm_device *dev = file_priv->minor->dev;
 587         struct drm_pending_event *e;
 588         unsigned long flags;
 589         bool ret = false;
 590
 591         spin_lock_irqsave(&dev->event_lock, flags);
 592
 593         *out = NULL;
 594         if (list_empty(&file_priv->event_list))
 595                 goto out;
 596         e = list_first_entry(&file_priv->event_list,
 597                              struct drm_pending_event, link);
 598         if (e->event->length + total > max)
 599                 goto out;
 600
 601         file_priv->event_space += e->event->length;
 602         list_del(&e->link);
 603         *out = e;
 604         ret = true;
 605
 606 out:
 607         spin_unlock_irqrestore(&dev->event_lock, flags);
 608         return ret;
 609 }
 610
 611 ssize_t drm_read(struct file *filp, char __user *buffer,
 612                  size_t count, loff_t *offset)
 613 {
 614         struct drm_file *file_priv = filp->private_data;
 615         struct drm_pending_event *e;
 616         size_t total;
 617         ssize_t ret;
 618
 619         ret = wait_event_interruptible(file_priv->event_wait,
 620                                        !list_empty(&file_priv->event_list));
 621         if (ret < 0)
 622                 return ret;
 623
 624         total = 0;
 625         while (drm_dequeue_event(file_priv, total, count, &e)) {
 626                 if (copy_to_user(buffer + total,
 627                                  e->event, e->event->length)) {
 628                         total = -EFAULT;
 629                         break;
 630                 }
 631
 632                 total += e->event->length;
 633                 e->destroy(e);
 634         }
 635
 636         return total;
 637 }
 638 EXPORT_SYMBOL(drm_read);
 639
 640 unsigned int drm_poll(struct file *filp, struct poll_table_struct *wait)
 641 {
 642         struct drm_file *file_priv = filp->private_data;
 643         unsigned int mask = 0;
 644
 645         poll_wait(filp, &file_priv->event_wait, wait);
 646
 647         if (!list_empty(&file_priv->event_list))
 648                 mask |= POLLIN | POLLRDNORM;
 649
 650         return mask;
 651 }
 652 EXPORT_SYMBOL(drm_poll);