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/module.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         if (dev->switch_power_state != DRM_SWITCH_POWER_ON)
 241                 return -EINVAL;
 242
 243         DRM_DEBUG("pid = %d, minor = %d\n", task_pid_nr(current), minor_id);
 244
 245         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 246         if (!priv)
 247                 return -ENOMEM;
 248
 249         filp->private_data = priv;
 250         priv->filp = filp;
 251         priv->uid = current_euid();
 252         priv->pid = task_pid_nr(current);
 253         priv->minor = idr_find(&drm_minors_idr, minor_id);
 254         priv->ioctl_count = 0;
 255         /* for compatibility root is always authenticated */
 256         priv->authenticated = capable(CAP_SYS_ADMIN);
 257         priv->lock_count = 0;
 258
 259         INIT_LIST_HEAD(&priv->lhead);
 260         INIT_LIST_HEAD(&priv->fbs);
 261         INIT_LIST_HEAD(&priv->event_list);
 262         init_waitqueue_head(&priv->event_wait);
 263         priv->event_space = 4096; /* set aside 4k for event buffer */
 264
 265         if (dev->driver->driver_features & DRIVER_GEM)
 266                 drm_gem_open(dev, priv);
 267
 268         if (dev->driver->open) {
 269                 ret = dev->driver->open(dev, priv);
 270                 if (ret < 0)
 271                         goto out_free;
 272         }
 273
 274
 275         /* if there is no current master make this fd it */
 276         mutex_lock(&dev->struct_mutex);
 277         if (!priv->minor->master) {
 278                 /* create a new master */
 279                 priv->minor->master = drm_master_create(priv->minor);
 280                 if (!priv->minor->master) {
 281                         mutex_unlock(&dev->struct_mutex);
 282                         ret = -ENOMEM;
 283                         goto out_free;
 284                 }
 285
 286                 priv->is_master = 1;
 287                 /* take another reference for the copy in the local file priv */
 288                 priv->master = drm_master_get(priv->minor->master);
 289
 290                 priv->authenticated = 1;
 291
 292                 mutex_unlock(&dev->struct_mutex);
 293                 if (dev->driver->master_create) {
 294                         ret = dev->driver->master_create(dev, priv->master);
 295                         if (ret) {
 296                                 mutex_lock(&dev->struct_mutex);
 297                                 /* drop both references if this fails */
 298                                 drm_master_put(&priv->minor->master);
 299                                 drm_master_put(&priv->master);
 300                                 mutex_unlock(&dev->struct_mutex);
 301                                 goto out_free;
 302                         }
 303                 }
 304                 mutex_lock(&dev->struct_mutex);
 305                 if (dev->driver->master_set) {
 306                         ret = dev->driver->master_set(dev, priv, true);
 307                         if (ret) {
 308                                 /* drop both references if this fails */
 309                                 drm_master_put(&priv->minor->master);
 310                                 drm_master_put(&priv->master);
 311                                 mutex_unlock(&dev->struct_mutex);
 312                                 goto out_free;
 313                         }
 314                 }
 315                 mutex_unlock(&dev->struct_mutex);
 316         } else {
 317                 /* get a reference to the master */
 318                 priv->master = drm_master_get(priv->minor->master);
 319                 mutex_unlock(&dev->struct_mutex);
 320         }
 321
 322         mutex_lock(&dev->struct_mutex);
 323         list_add(&priv->lhead, &dev->filelist);
 324         mutex_unlock(&dev->struct_mutex);
 325
 326 #ifdef __alpha__
 327         /*
 328          * Default the hose
 329          */
 330         if (!dev->hose) {
 331                 struct pci_dev *pci_dev;
 332                 pci_dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
 333                 if (pci_dev) {
 334                         dev->hose = pci_dev->sysdata;
 335                         pci_dev_put(pci_dev);
 336                 }
 337                 if (!dev->hose) {
 338                         struct pci_bus *b = pci_bus_b(pci_root_buses.next);
 339                         if (b)
 340                                 dev->hose = b->sysdata;
 341                 }
 342         }
 343 #endif
 344
 345         return 0;
 346       out_free:
 347         kfree(priv);
 348         filp->private_data = NULL;
 349         return ret;
 350 }
 351
 352 /** No-op. */
 353 int drm_fasync(int fd, struct file *filp, int on)
 354 {
 355         struct drm_file *priv = filp->private_data;
 356         struct drm_device *dev = priv->minor->dev;
 357
 358         DRM_DEBUG("fd = %d, device = 0x%lx\n", fd,
 359                   (long)old_encode_dev(priv->minor->device));
 360         return fasync_helper(fd, filp, on, &dev->buf_async);
 361 }
 362 EXPORT_SYMBOL(drm_fasync);
 363
 364 /*
 365  * Reclaim locked buffers; note that this may be a bad idea if the current
 366  * context doesn't have the hw lock...
 367  */
 368 static void drm_reclaim_locked_buffers(struct drm_device *dev, struct file *f)
 369 {
 370         struct drm_file *file_priv = f->private_data;
 371
 372         if (drm_i_have_hw_lock(dev, file_priv)) {
 373                 dev->driver->reclaim_buffers_locked(dev, file_priv);
 374         } else {
 375                 unsigned long _end = jiffies + 3 * DRM_HZ;
 376                 int locked = 0;
 377
 378                 drm_idlelock_take(&file_priv->master->lock);
 379
 380                 /*
 381                  * Wait for a while.
 382                  */
 383                 do {
 384                         spin_lock_bh(&file_priv->master->lock.spinlock);
 385                         locked = file_priv->master->lock.idle_has_lock;
 386                         spin_unlock_bh(&file_priv->master->lock.spinlock);
 387                         if (locked)
 388                                 break;
 389                         schedule();
 390                 } while (!time_after_eq(jiffies, _end));
 391
 392                 if (!locked) {
 393                         DRM_ERROR("reclaim_buffers_locked() deadlock. Please rework this\n"
 394                                   "\tdriver to use reclaim_buffers_idlelocked() instead.\n"
 395                                   "\tI will go on reclaiming the buffers anyway.\n");
 396                 }
 397
 398                 dev->driver->reclaim_buffers_locked(dev, file_priv);
 399                 drm_idlelock_release(&file_priv->master->lock);
 400         }
 401 }
 402
 403 static void drm_master_release(struct drm_device *dev, struct file *filp)
 404 {
 405         struct drm_file *file_priv = filp->private_data;
 406
 407         if (dev->driver->reclaim_buffers_locked &&
 408             file_priv->master->lock.hw_lock)
 409                 drm_reclaim_locked_buffers(dev, filp);
 410
 411         if (dev->driver->reclaim_buffers_idlelocked &&
 412             file_priv->master->lock.hw_lock) {
 413                 drm_idlelock_take(&file_priv->master->lock);
 414                 dev->driver->reclaim_buffers_idlelocked(dev, file_priv);
 415                 drm_idlelock_release(&file_priv->master->lock);
 416         }
 417
 418
 419         if (drm_i_have_hw_lock(dev, file_priv)) {
 420                 DRM_DEBUG("File %p released, freeing lock for context %d\n",
 421                           filp, _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
 422                 drm_lock_free(&file_priv->master->lock,
 423                               _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
 424         }
 425
 426         if (drm_core_check_feature(dev, DRIVER_HAVE_DMA) &&
 427             !dev->driver->reclaim_buffers_locked) {
 428                 dev->driver->reclaim_buffers(dev, file_priv);
 429         }
 430 }
 431
 432 static void drm_events_release(struct drm_file *file_priv)
 433 {
 434         struct drm_device *dev = file_priv->minor->dev;
 435         struct drm_pending_event *e, *et;
 436         struct drm_pending_vblank_event *v, *vt;
 437         unsigned long flags;
 438
 439         spin_lock_irqsave(&dev->event_lock, flags);
 440
 441         /* Remove pending flips */
 442         list_for_each_entry_safe(v, vt, &dev->vblank_event_list, base.link)
 443                 if (v->base.file_priv == file_priv) {
 444                         list_del(&v->base.link);
 445                         drm_vblank_put(dev, v->pipe);
 446                         v->base.destroy(&v->base);
 447                 }
 448
 449         /* Remove unconsumed events */
 450         list_for_each_entry_safe(e, et, &file_priv->event_list, link)
 451                 e->destroy(e);
 452
 453         spin_unlock_irqrestore(&dev->event_lock, flags);
 454 }
 455
 456 /**
 457  * Release file.
 458  *
 459  * \param inode device inode
 460  * \param file_priv DRM file private.
 461  * \return zero on success or a negative number on failure.
 462  *
 463  * If the hardware lock is held then free it, and take it again for the kernel
 464  * context since it's necessary to reclaim buffers. Unlink the file private
 465  * data from its list and free it. Decreases the open count and if it reaches
 466  * zero calls drm_lastclose().
 467  */
 468 int drm_release(struct inode *inode, struct file *filp)
 469 {
 470         struct drm_file *file_priv = filp->private_data;
 471         struct drm_device *dev = file_priv->minor->dev;
 472         int retcode = 0;
 473
 474         mutex_lock(&drm_global_mutex);
 475
 476         DRM_DEBUG("open_count = %d\n", dev->open_count);
 477
 478         if (dev->driver->preclose)
 479                 dev->driver->preclose(dev, file_priv);
 480
 481         /* ========================================================
 482          * Begin inline drm_release
 483          */
 484
 485         DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
 486                   task_pid_nr(current),
 487                   (long)old_encode_dev(file_priv->minor->device),
 488                   dev->open_count);
 489
 490         /* Release any auth tokens that might point to this file_priv,
 491            (do that under the drm_global_mutex) */
 492         if (file_priv->magic)
 493                 (void) drm_remove_magic(file_priv->master, file_priv->magic);
 494
 495         /* if the master has gone away we can't do anything with the lock */
 496         if (file_priv->minor->master)
 497                 drm_master_release(dev, filp);
 498
 499         drm_events_release(file_priv);
 500
 501         if (dev->driver->driver_features & DRIVER_GEM)
 502                 drm_gem_release(dev, file_priv);
 503
 504         if (dev->driver->driver_features & DRIVER_MODESET)
 505                 drm_fb_release(file_priv);
 506
 507         mutex_lock(&dev->ctxlist_mutex);
 508         if (!list_empty(&dev->ctxlist)) {
 509                 struct drm_ctx_list *pos, *n;
 510
 511                 list_for_each_entry_safe(pos, n, &dev->ctxlist, head) {
 512                         if (pos->tag == file_priv &&
 513                             pos->handle != DRM_KERNEL_CONTEXT) {
 514                                 if (dev->driver->context_dtor)
 515                                         dev->driver->context_dtor(dev,
 516                                                                   pos->handle);
 517
 518                                 drm_ctxbitmap_free(dev, pos->handle);
 519
 520                                 list_del(&pos->head);
 521                                 kfree(pos);
 522                                 --dev->ctx_count;
 523                         }
 524                 }
 525         }
 526         mutex_unlock(&dev->ctxlist_mutex);
 527
 528         mutex_lock(&dev->struct_mutex);
 529
 530         if (file_priv->is_master) {
 531                 struct drm_master *master = file_priv->master;
 532                 struct drm_file *temp;
 533                 list_for_each_entry(temp, &dev->filelist, lhead) {
 534                         if ((temp->master == file_priv->master) &&
 535                             (temp != file_priv))
 536                                 temp->authenticated = 0;
 537                 }
 538
 539                 /**
 540                  * Since the master is disappearing, so is the
 541                  * possibility to lock.
 542                  */
 543
 544                 if (master->lock.hw_lock) {
 545                         if (dev->sigdata.lock == master->lock.hw_lock)
 546                                 dev->sigdata.lock = NULL;
 547                         master->lock.hw_lock = NULL;
 548                         master->lock.file_priv = NULL;
 549                         wake_up_interruptible_all(&master->lock.lock_queue);
 550                 }
 551
 552                 if (file_priv->minor->master == file_priv->master) {
 553                         /* drop the reference held my the minor */
 554                         if (dev->driver->master_drop)
 555                                 dev->driver->master_drop(dev, file_priv, true);
 556                         drm_master_put(&file_priv->minor->master);
 557                 }
 558         }
 559
 560         /* drop the reference held my the file priv */
 561         drm_master_put(&file_priv->master);
 562         file_priv->is_master = 0;
 563         list_del(&file_priv->lhead);
 564         mutex_unlock(&dev->struct_mutex);
 565
 566         if (dev->driver->postclose)
 567                 dev->driver->postclose(dev, file_priv);
 568         kfree(file_priv);
 569
 570         /* ========================================================
 571          * End inline drm_release
 572          */
 573
 574         atomic_inc(&dev->counts[_DRM_STAT_CLOSES]);
 575         if (!--dev->open_count) {
 576                 if (atomic_read(&dev->ioctl_count)) {
 577                         DRM_ERROR("Device busy: %d\n",
 578                                   atomic_read(&dev->ioctl_count));
 579                         retcode = -EBUSY;
 580                 } else
 581                         retcode = drm_lastclose(dev);
 582         }
 583         mutex_unlock(&drm_global_mutex);
 584
 585         return retcode;
 586 }
 587 EXPORT_SYMBOL(drm_release);
 588
 589 static bool
 590 drm_dequeue_event(struct drm_file *file_priv,
 591                   size_t total, size_t max, struct drm_pending_event **out)
 592 {
 593         struct drm_device *dev = file_priv->minor->dev;
 594         struct drm_pending_event *e;
 595         unsigned long flags;
 596         bool ret = false;
 597
 598         spin_lock_irqsave(&dev->event_lock, flags);
 599
 600         *out = NULL;
 601         if (list_empty(&file_priv->event_list))
 602                 goto out;
 603         e = list_first_entry(&file_priv->event_list,
 604                              struct drm_pending_event, link);
 605         if (e->event->length + total > max)
 606                 goto out;
 607
 608         file_priv->event_space += e->event->length;
 609         list_del(&e->link);
 610         *out = e;
 611         ret = true;
 612
 613 out:
 614         spin_unlock_irqrestore(&dev->event_lock, flags);
 615         return ret;
 616 }
 617
 618 ssize_t drm_read(struct file *filp, char __user *buffer,
 619                  size_t count, loff_t *offset)
 620 {
 621         struct drm_file *file_priv = filp->private_data;
 622         struct drm_pending_event *e;
 623         size_t total;
 624         ssize_t ret;
 625
 626         ret = wait_event_interruptible(file_priv->event_wait,
 627                                        !list_empty(&file_priv->event_list));
 628         if (ret < 0)
 629                 return ret;
 630
 631         total = 0;
 632         while (drm_dequeue_event(file_priv, total, count, &e)) {
 633                 if (copy_to_user(buffer + total,
 634                                  e->event, e->event->length)) {
 635                         total = -EFAULT;
 636                         break;
 637                 }
 638
 639                 total += e->event->length;
 640                 e->destroy(e);
 641         }
 642
 643         return total;
 644 }
 645 EXPORT_SYMBOL(drm_read);
 646
 647 unsigned int drm_poll(struct file *filp, struct poll_table_struct *wait)
 648 {
 649         struct drm_file *file_priv = filp->private_data;
 650         unsigned int mask = 0;
 651
 652         poll_wait(filp, &file_priv->event_wait, wait);
 653
 654         if (!list_empty(&file_priv->event_list))
 655                 mask |= POLLIN | POLLRDNORM;
 656
 657         return mask;
 658 }
 659 EXPORT_SYMBOL(drm_poll);