linux-core/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 "drm_sarea.h"
  39 #include <linux/poll.h>
  40
  41 static int drm_open_helper(struct inode *inode, struct file *filp,
  42                            drm_device_t * dev);
  43
  44 static int drm_setup(drm_device_t * dev)
  45 {
  46         drm_local_map_t *map;
  47         int i;
  48         int ret;
  49         int sareapage;
  50
  51         if (dev->driver->firstopen) {
  52                 ret = dev->driver->firstopen(dev);
  53                 if (ret != 0)
  54                         return ret;
  55         }
  56
  57         dev->magicfree.next = NULL;
  58
  59         /* prebuild the SAREA */
  60         sareapage = max(SAREA_MAX, PAGE_SIZE);
  61         i = drm_addmap(dev, 0, sareapage, _DRM_SHM, _DRM_CONTAINS_LOCK, &map);
  62         if (i != 0)
  63                 return i;
  64
  65         atomic_set(&dev->ioctl_count, 0);
  66         atomic_set(&dev->vma_count, 0);
  67         dev->buf_use = 0;
  68         atomic_set(&dev->buf_alloc, 0);
  69
  70         if (drm_core_check_feature(dev, DRIVER_HAVE_DMA)) {
  71                 i = drm_dma_setup(dev);
  72                 if (i < 0)
  73                         return i;
  74         }
  75
  76         for (i = 0; i < ARRAY_SIZE(dev->counts); i++)
  77                 atomic_set(&dev->counts[i], 0);
  78
  79         drm_ht_create(&dev->magiclist, DRM_MAGIC_HASH_ORDER);
  80         INIT_LIST_HEAD(&dev->magicfree);
  81
  82         dev->ctxlist = drm_alloc(sizeof(*dev->ctxlist), DRM_MEM_CTXLIST);
  83         if (dev->ctxlist == NULL)
  84                 return -ENOMEM;
  85         memset(dev->ctxlist, 0, sizeof(*dev->ctxlist));
  86         INIT_LIST_HEAD(&dev->ctxlist->head);
  87
  88         dev->vmalist = NULL;
  89         dev->sigdata.lock = NULL;
  90         init_waitqueue_head(&dev->lock.lock_queue);
  91         dev->queue_count = 0;
  92         dev->queue_reserved = 0;
  93         dev->queue_slots = 0;
  94         dev->queuelist = NULL;
  95         dev->irq_enabled = 0;
  96         dev->context_flag = 0;
  97         dev->interrupt_flag = 0;
  98         dev->dma_flag = 0;
  99         dev->last_context = 0;
 100         dev->last_switch = 0;
 101         dev->last_checked = 0;
 102         init_waitqueue_head(&dev->context_wait);
 103         dev->if_version = 0;
 104
 105         dev->ctx_start = 0;
 106         dev->lck_start = 0;
 107
 108         dev->buf_async = NULL;
 109         init_waitqueue_head(&dev->buf_readers);
 110         init_waitqueue_head(&dev->buf_writers);
 111
 112         DRM_DEBUG("\n");
 113
 114         /*
 115          * The kernel's context could be created here, but is now created
 116          * in drm_dma_enqueue.  This is more resource-efficient for
 117          * hardware that does not do DMA, but may mean that
 118          * drm_select_queue fails between the time the interrupt is
 119          * initialized and the time the queues are initialized.
 120          */
 121
 122         return 0;
 123 }
 124
 125 /**
 126  * Open file.
 127  *
 128  * \param inode device inode
 129  * \param filp file pointer.
 130  * \return zero on success or a negative number on failure.
 131  *
 132  * Searches the DRM device with the same minor number, calls open_helper(), and
 133  * increments the device open count. If the open count was previous at zero,
 134  * i.e., it's the first that the device is open, then calls setup().
 135  */
 136 int drm_open(struct inode *inode, struct file *filp)
 137 {
 138         drm_device_t *dev = NULL;
 139         int minor = iminor(inode);
 140         int retcode = 0;
 141
 142         if (!((minor >= 0) && (minor < drm_cards_limit)))
 143                 return -ENODEV;
 144
 145         if (!drm_heads[minor])
 146                 return -ENODEV;
 147
 148         if (!(dev = drm_heads[minor]->dev))
 149                 return -ENODEV;
 150
 151         retcode = drm_open_helper(inode, filp, dev);
 152         if (!retcode) {
 153                 atomic_inc(&dev->counts[_DRM_STAT_OPENS]);
 154                 spin_lock(&dev->count_lock);
 155                 if (!dev->open_count++) {
 156                         spin_unlock(&dev->count_lock);
 157                         return drm_setup(dev);
 158                 }
 159                 spin_unlock(&dev->count_lock);
 160         }
 161         mutex_lock(&dev->struct_mutex);
 162         BUG_ON((dev->dev_mapping != NULL) &&
 163                (dev->dev_mapping != inode->i_mapping));
 164         if (dev->dev_mapping == NULL)
 165                 dev->dev_mapping = inode->i_mapping;
 166         mutex_unlock(&dev->struct_mutex);
 167
 168         return retcode;
 169 }
 170 EXPORT_SYMBOL(drm_open);
 171
 172 /**
 173  * File \c open operation.
 174  *
 175  * \param inode device inode.
 176  * \param filp file pointer.
 177  *
 178  * Puts the dev->fops corresponding to the device minor number into
 179  * \p filp, call the \c open method, and restore the file operations.
 180  */
 181 int drm_stub_open(struct inode *inode, struct file *filp)
 182 {
 183         drm_device_t *dev = NULL;
 184         int minor = iminor(inode);
 185         int err = -ENODEV;
 186         const struct file_operations *old_fops;
 187
 188         DRM_DEBUG("\n");
 189
 190         if (!((minor >= 0) && (minor < drm_cards_limit)))
 191                 return -ENODEV;
 192
 193         if (!drm_heads[minor])
 194                 return -ENODEV;
 195
 196         if (!(dev = drm_heads[minor]->dev))
 197                 return -ENODEV;
 198
 199         old_fops = filp->f_op;
 200         filp->f_op = fops_get(&dev->driver->fops);
 201         if (filp->f_op->open && (err = filp->f_op->open(inode, filp))) {
 202                 fops_put(filp->f_op);
 203                 filp->f_op = fops_get(old_fops);
 204         }
 205         fops_put(old_fops);
 206
 207         return err;
 208 }
 209
 210 /**
 211  * Check whether DRI will run on this CPU.
 212  *
 213  * \return non-zero if the DRI will run on this CPU, or zero otherwise.
 214  */
 215 static int drm_cpu_valid(void)
 216 {
 217 #if defined(__i386__)
 218         if (boot_cpu_data.x86 == 3)
 219                 return 0;       /* No cmpxchg on a 386 */
 220 #endif
 221 #if defined(__sparc__) && !defined(__sparc_v9__)
 222         return 0;               /* No cmpxchg before v9 sparc. */
 223 #endif
 224         return 1;
 225 }
 226
 227 /**
 228  * Called whenever a process opens /dev/drm.
 229  *
 230  * \param inode device inode.
 231  * \param filp file pointer.
 232  * \param dev device.
 233  * \return zero on success or a negative number on failure.
 234  *
 235  * Creates and initializes a drm_file structure for the file private data in \p
 236  * filp and add it into the double linked list in \p dev.
 237  */
 238 static int drm_open_helper(struct inode *inode, struct file *filp,
 239                            drm_device_t * dev)
 240 {
 241         int minor = iminor(inode);
 242         drm_file_t *priv;
 243         int ret;
 244         int i,j;
 245
 246         if (filp->f_flags & O_EXCL)
 247                 return -EBUSY;  /* No exclusive opens */
 248         if (!drm_cpu_valid())
 249                 return -EINVAL;
 250
 251         DRM_DEBUG("pid = %d, minor = %d\n", current->pid, minor);
 252
 253         priv = drm_alloc(sizeof(*priv), DRM_MEM_FILES);
 254         if (!priv)
 255                 return -ENOMEM;
 256
 257         memset(priv, 0, sizeof(*priv));
 258         filp->private_data = priv;
 259         priv->uid = current->euid;
 260         priv->pid = current->pid;
 261         priv->minor = minor;
 262         priv->head = drm_heads[minor];
 263         priv->ioctl_count = 0;
 264         /* for compatibility root is always authenticated */
 265         priv->authenticated = capable(CAP_SYS_ADMIN);
 266         priv->lock_count = 0;
 267
 268         INIT_LIST_HEAD(&priv->user_objects);
 269         INIT_LIST_HEAD(&priv->refd_objects);
 270
 271         for (i=0; i<_DRM_NO_REF_TYPES; ++i) {
 272                 ret = drm_ht_create(&priv->refd_object_hash[i], DRM_FILE_HASH_ORDER);
 273                 if (ret)
 274                         break;
 275         }
 276
 277         if (ret) {
 278                 for(j=0; j<i; ++j) {
 279                         drm_ht_remove(&priv->refd_object_hash[j]);
 280                 }
 281                 goto out_free;
 282         }
 283
 284         if (dev->driver->open) {
 285                 ret = dev->driver->open(dev, priv);
 286                 if (ret < 0)
 287                         goto out_free;
 288         }
 289
 290         mutex_lock(&dev->struct_mutex);
 291         if (!dev->file_last) {
 292                 priv->next = NULL;
 293                 priv->prev = NULL;
 294                 dev->file_first = priv;
 295                 dev->file_last = priv;
 296                 /* first opener automatically becomes master */
 297                 priv->master = 1;
 298         } else {
 299                 priv->next = NULL;
 300                 priv->prev = dev->file_last;
 301                 dev->file_last->next = priv;
 302                 dev->file_last = priv;
 303         }
 304         mutex_unlock(&dev->struct_mutex);
 305
 306 #ifdef __alpha__
 307         /*
 308          * Default the hose
 309          */
 310         if (!dev->hose) {
 311                 struct pci_dev *pci_dev;
 312                 pci_dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
 313                 if (pci_dev) {
 314                         dev->hose = pci_dev->sysdata;
 315                         pci_dev_put(pci_dev);
 316                 }
 317                 if (!dev->hose) {
 318                         struct pci_bus *b = pci_bus_b(pci_root_buses.next);
 319                         if (b)
 320                                 dev->hose = b->sysdata;
 321                 }
 322         }
 323 #endif
 324
 325         return 0;
 326       out_free:
 327         drm_free(priv, sizeof(*priv), DRM_MEM_FILES);
 328         filp->private_data = NULL;
 329         return ret;
 330 }
 331
 332 /** No-op. */
 333 int drm_fasync(int fd, struct file *filp, int on)
 334 {
 335         drm_file_t *priv = filp->private_data;
 336         drm_device_t *dev = priv->head->dev;
 337         int retcode;
 338
 339         DRM_DEBUG("fd = %d, device = 0x%lx\n", fd,
 340                   (long)old_encode_dev(priv->head->device));
 341         retcode = fasync_helper(fd, filp, on, &dev->buf_async);
 342         if (retcode < 0)
 343                 return retcode;
 344         return 0;
 345 }
 346 EXPORT_SYMBOL(drm_fasync);
 347
 348 static void drm_object_release(struct file *filp) {
 349
 350         drm_file_t *priv = filp->private_data;
 351         struct list_head *head;
 352         drm_user_object_t *user_object;
 353         drm_ref_object_t *ref_object;
 354         int i;
 355
 356         /*
 357          * Free leftover ref objects created by me. Note that we cannot use
 358          * list_for_each() here, as the struct_mutex may be temporarily released
 359          * by the remove_() functions, and thus the lists may be altered.
 360          * Also, a drm_remove_ref_object() will not remove it
 361          * from the list unless its refcount is 1.
 362          */
 363
 364         head = &priv->refd_objects;
 365         while (head->next != head) {
 366                 ref_object = list_entry(head->next, drm_ref_object_t, list);
 367                 drm_remove_ref_object(priv, ref_object);
 368                 head = &priv->refd_objects;
 369         }
 370
 371         /*
 372          * Free leftover user objects created by me.
 373          */
 374
 375         head = &priv->user_objects;
 376         while (head->next != head) {
 377                 user_object = list_entry(head->next, drm_user_object_t, list);
 378                 drm_remove_user_object(priv, user_object);
 379                 head = &priv->user_objects;
 380         }
 381
 382
 383
 384
 385         for(i=0; i<_DRM_NO_REF_TYPES; ++i) {
 386                 drm_ht_remove(&priv->refd_object_hash[i]);
 387         }
 388 }
 389
 390
 391
 392
 393
 394
 395 /**
 396  * Release file.
 397  *
 398  * \param inode device inode
 399  * \param filp file pointer.
 400  * \return zero on success or a negative number on failure.
 401  *
 402  * If the hardware lock is held then free it, and take it again for the kernel
 403  * context since it's necessary to reclaim buffers. Unlink the file private
 404  * data from its list and free it. Decreases the open count and if it reaches
 405  * zero calls drm_lastclose().
 406  */
 407 int drm_release(struct inode *inode, struct file *filp)
 408 {
 409         drm_file_t *priv = filp->private_data;
 410         drm_device_t *dev;
 411         int retcode = 0;
 412
 413         lock_kernel();
 414         dev = priv->head->dev;
 415
 416         DRM_DEBUG("open_count = %d\n", dev->open_count);
 417
 418         if (dev->driver->preclose)
 419                 dev->driver->preclose(dev, filp);
 420
 421         /* ========================================================
 422          * Begin inline drm_release
 423          */
 424
 425         DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
 426                   current->pid, (long)old_encode_dev(priv->head->device),
 427                   dev->open_count);
 428
 429         if (dev->driver->reclaim_buffers_locked && dev->lock.hw_lock) {
 430                 unsigned long _end = jiffies + DRM_HZ*3;
 431
 432                 do {
 433                         retcode = drm_kernel_take_hw_lock(filp);
 434                 } while(retcode && !time_after_eq(jiffies,_end));
 435
 436                 if (!retcode) {
 437                         dev->driver->reclaim_buffers_locked(dev, filp);
 438
 439                         drm_lock_free(dev, &dev->lock.hw_lock->lock,
 440                                       _DRM_LOCKING_CONTEXT(dev->lock.hw_lock->lock));
 441                 } else {
 442
 443                         /*
 444                          * FIXME: This is not a good solution. We should perhaps associate the
 445                          * DRM lock with a process context, and check whether the current process
 446                          * holds the lock. Then we can run reclaim buffers locked anyway.
 447                          */
 448
 449                         DRM_ERROR("Reclaim buffers locked deadlock.\n"
 450                                   "\tThis is probably a single thread having multiple\n"
 451                                   "\tDRM file descriptors open either dying or"
 452                                   " closing file descriptors\n"
 453                                   "\twhile having the lock. I will not reclaim buffers.\n"
 454                                   "\tLocking context is 0x%08x\n",
 455                                   _DRM_LOCKING_CONTEXT(dev->lock.hw_lock->lock));
 456                 }
 457         } else if (drm_i_have_hw_lock(filp)) {
 458                 DRM_DEBUG("File %p released, freeing lock for context %d\n",
 459                           filp, _DRM_LOCKING_CONTEXT(dev->lock.hw_lock->lock));
 460
 461                 drm_lock_free(dev, &dev->lock.hw_lock->lock,
 462                               _DRM_LOCKING_CONTEXT(dev->lock.hw_lock->lock));
 463         }
 464
 465
 466         if (drm_core_check_feature(dev, DRIVER_HAVE_DMA) &&
 467             !dev->driver->reclaim_buffers_locked) {
 468                 dev->driver->reclaim_buffers(dev, filp);
 469         }
 470
 471         drm_fasync(-1, filp, 0);
 472
 473         mutex_lock(&dev->ctxlist_mutex);
 474
 475         if (dev->ctxlist && (!list_empty(&dev->ctxlist->head))) {
 476                 drm_ctx_list_t *pos, *n;
 477
 478                 list_for_each_entry_safe(pos, n, &dev->ctxlist->head, head) {
 479                         if (pos->tag == priv &&
 480                             pos->handle != DRM_KERNEL_CONTEXT) {
 481                                 if (dev->driver->context_dtor)
 482                                         dev->driver->context_dtor(dev,
 483                                                                   pos->handle);
 484
 485                                 drm_ctxbitmap_free(dev, pos->handle);
 486
 487                                 list_del(&pos->head);
 488                                 drm_free(pos, sizeof(*pos), DRM_MEM_CTXLIST);
 489                                 --dev->ctx_count;
 490                         }
 491                 }
 492         }
 493         mutex_unlock(&dev->ctxlist_mutex);
 494
 495         mutex_lock(&dev->struct_mutex);
 496         drm_object_release(filp);
 497         if (priv->remove_auth_on_close == 1) {
 498                 drm_file_t *temp = dev->file_first;
 499                 while (temp) {
 500                         temp->authenticated = 0;
 501                         temp = temp->next;
 502                 }
 503         }
 504         if (priv->prev) {
 505                 priv->prev->next = priv->next;
 506         } else {
 507                 dev->file_first = priv->next;
 508         }
 509         if (priv->next) {
 510                 priv->next->prev = priv->prev;
 511         } else {
 512                 dev->file_last = priv->prev;
 513         }
 514         mutex_unlock(&dev->struct_mutex);
 515
 516         if (dev->driver->postclose)
 517                 dev->driver->postclose(dev, priv);
 518         drm_free(priv, sizeof(*priv), DRM_MEM_FILES);
 519
 520         /* ========================================================
 521          * End inline drm_release
 522          */
 523
 524         atomic_inc(&dev->counts[_DRM_STAT_CLOSES]);
 525         spin_lock(&dev->count_lock);
 526         if (!--dev->open_count) {
 527                 if (atomic_read(&dev->ioctl_count) || dev->blocked) {
 528                         DRM_ERROR("Device busy: %d %d\n",
 529                                   atomic_read(&dev->ioctl_count), dev->blocked);
 530                         spin_unlock(&dev->count_lock);
 531                         unlock_kernel();
 532                         return -EBUSY;
 533                 }
 534                 spin_unlock(&dev->count_lock);
 535                 unlock_kernel();
 536                 return drm_lastclose(dev);
 537         }
 538         spin_unlock(&dev->count_lock);
 539
 540         unlock_kernel();
 541
 542         return retcode;
 543 }
 544 EXPORT_SYMBOL(drm_release);
 545
 546 /** No-op. */
 547 /* This is to deal with older X servers that believe 0 means data is
 548  * available which is not the correct return for a poll function.
 549  * This cannot be fixed until the Xserver is fixed. Xserver will need
 550  * to set a newer interface version to avoid breaking older Xservers.
 551  * Without fixing the Xserver you get: "WaitForSomething(): select: errno=22"
 552  * http://freedesktop.org/bugzilla/show_bug.cgi?id=1505 if you try
 553  * to return the correct response.
 554  */
 555 unsigned int drm_poll(struct file *filp, struct poll_table_struct *wait)
 556 {
 557         /* return (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM); */
 558         return 0;
 559 }
 560 EXPORT_SYMBOL(drm_poll);
 561