drivers/char/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 "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
  50         if (dev->driver->firstopen) {
  51                 ret = dev->driver->firstopen(dev);
  52                 if (ret != 0)
  53                         return ret;
  54         }
  55
  56         /* prebuild the SAREA */
  57         i = drm_addmap(dev, 0, SAREA_MAX, _DRM_SHM, _DRM_CONTAINS_LOCK, &map);
  58         if (i != 0)
  59                 return i;
  60
  61         atomic_set(&dev->ioctl_count, 0);
  62         atomic_set(&dev->vma_count, 0);
  63         dev->buf_use = 0;
  64         atomic_set(&dev->buf_alloc, 0);
  65
  66         if (drm_core_check_feature(dev, DRIVER_HAVE_DMA)) {
  67                 i = drm_dma_setup(dev);
  68                 if (i < 0)
  69                         return i;
  70         }
  71
  72         for (i = 0; i < ARRAY_SIZE(dev->counts); i++)
  73                 atomic_set(&dev->counts[i], 0);
  74
  75         drm_ht_create(&dev->magiclist, DRM_MAGIC_HASH_ORDER);
  76         INIT_LIST_HEAD(&dev->magicfree);
  77
  78         dev->ctxlist = drm_alloc(sizeof(*dev->ctxlist), DRM_MEM_CTXLIST);
  79         if (dev->ctxlist == NULL)
  80                 return -ENOMEM;
  81         memset(dev->ctxlist, 0, sizeof(*dev->ctxlist));
  82         INIT_LIST_HEAD(&dev->ctxlist->head);
  83
  84         dev->vmalist = NULL;
  85         dev->sigdata.lock = dev->lock.hw_lock = NULL;
  86         init_waitqueue_head(&dev->lock.lock_queue);
  87         dev->queue_count = 0;
  88         dev->queue_reserved = 0;
  89         dev->queue_slots = 0;
  90         dev->queuelist = NULL;
  91         dev->irq_enabled = 0;
  92         dev->context_flag = 0;
  93         dev->interrupt_flag = 0;
  94         dev->dma_flag = 0;
  95         dev->last_context = 0;
  96         dev->last_switch = 0;
  97         dev->last_checked = 0;
  98         init_waitqueue_head(&dev->context_wait);
  99         dev->if_version = 0;
 100
 101         dev->ctx_start = 0;
 102         dev->lck_start = 0;
 103
 104         dev->buf_async = NULL;
 105         init_waitqueue_head(&dev->buf_readers);
 106         init_waitqueue_head(&dev->buf_writers);
 107
 108         DRM_DEBUG("\n");
 109
 110         /*
 111          * The kernel's context could be created here, but is now created
 112          * in drm_dma_enqueue.  This is more resource-efficient for
 113          * hardware that does not do DMA, but may mean that
 114          * drm_select_queue fails between the time the interrupt is
 115          * initialized and the time the queues are initialized.
 116          */
 117
 118         return 0;
 119 }
 120
 121 /**
 122  * Open file.
 123  *
 124  * \param inode device inode
 125  * \param filp file pointer.
 126  * \return zero on success or a negative number on failure.
 127  *
 128  * Searches the DRM device with the same minor number, calls open_helper(), and
 129  * increments the device open count. If the open count was previous at zero,
 130  * i.e., it's the first that the device is open, then calls setup().
 131  */
 132 int drm_open(struct inode *inode, struct file *filp)
 133 {
 134         drm_device_t *dev = NULL;
 135         int minor = iminor(inode);
 136         int retcode = 0;
 137
 138         if (!((minor >= 0) && (minor < drm_cards_limit)))
 139                 return -ENODEV;
 140
 141         if (!drm_heads[minor])
 142                 return -ENODEV;
 143
 144         if (!(dev = drm_heads[minor]->dev))
 145                 return -ENODEV;
 146
 147         retcode = drm_open_helper(inode, filp, dev);
 148         if (!retcode) {
 149                 atomic_inc(&dev->counts[_DRM_STAT_OPENS]);
 150                 spin_lock(&dev->count_lock);
 151                 if (!dev->open_count++) {
 152                         spin_unlock(&dev->count_lock);
 153                         return drm_setup(dev);
 154                 }
 155                 spin_unlock(&dev->count_lock);
 156         }
 157
 158         return retcode;
 159 }
 160 EXPORT_SYMBOL(drm_open);
 161
 162 /**
 163  * File \c open operation.
 164  *
 165  * \param inode device inode.
 166  * \param filp file pointer.
 167  *
 168  * Puts the dev->fops corresponding to the device minor number into
 169  * \p filp, call the \c open method, and restore the file operations.
 170  */
 171 int drm_stub_open(struct inode *inode, struct file *filp)
 172 {
 173         drm_device_t *dev = NULL;
 174         int minor = iminor(inode);
 175         int err = -ENODEV;
 176         const struct file_operations *old_fops;
 177
 178         DRM_DEBUG("\n");
 179
 180         if (!((minor >= 0) && (minor < drm_cards_limit)))
 181                 return -ENODEV;
 182
 183         if (!drm_heads[minor])
 184                 return -ENODEV;
 185
 186         if (!(dev = drm_heads[minor]->dev))
 187                 return -ENODEV;
 188
 189         old_fops = filp->f_op;
 190         filp->f_op = fops_get(&dev->driver->fops);
 191         if (filp->f_op->open && (err = filp->f_op->open(inode, filp))) {
 192                 fops_put(filp->f_op);
 193                 filp->f_op = fops_get(old_fops);
 194         }
 195         fops_put(old_fops);
 196
 197         return err;
 198 }
 199
 200 /**
 201  * Check whether DRI will run on this CPU.
 202  *
 203  * \return non-zero if the DRI will run on this CPU, or zero otherwise.
 204  */
 205 static int drm_cpu_valid(void)
 206 {
 207 #if defined(__i386__)
 208         if (boot_cpu_data.x86 == 3)
 209                 return 0;       /* No cmpxchg on a 386 */
 210 #endif
 211 #if defined(__sparc__) && !defined(__sparc_v9__)
 212         return 0;               /* No cmpxchg before v9 sparc. */
 213 #endif
 214         return 1;
 215 }
 216
 217 /**
 218  * Called whenever a process opens /dev/drm.
 219  *
 220  * \param inode device inode.
 221  * \param filp file pointer.
 222  * \param dev device.
 223  * \return zero on success or a negative number on failure.
 224  *
 225  * Creates and initializes a drm_file structure for the file private data in \p
 226  * filp and add it into the double linked list in \p dev.
 227  */
 228 static int drm_open_helper(struct inode *inode, struct file *filp,
 229                            drm_device_t * dev)
 230 {
 231         int minor = iminor(inode);
 232         drm_file_t *priv;
 233         int ret;
 234
 235         if (filp->f_flags & O_EXCL)
 236                 return -EBUSY;  /* No exclusive opens */
 237         if (!drm_cpu_valid())
 238                 return -EINVAL;
 239
 240         DRM_DEBUG("pid = %d, minor = %d\n", current->pid, minor);
 241
 242         priv = drm_alloc(sizeof(*priv), DRM_MEM_FILES);
 243         if (!priv)
 244                 return -ENOMEM;
 245
 246         memset(priv, 0, sizeof(*priv));
 247         filp->private_data = priv;
 248         priv->uid = current->euid;
 249         priv->pid = current->pid;
 250         priv->minor = minor;
 251         priv->head = drm_heads[minor];
 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         if (dev->driver->open) {
 258                 ret = dev->driver->open(dev, priv);
 259                 if (ret < 0)
 260                         goto out_free;
 261         }
 262
 263         mutex_lock(&dev->struct_mutex);
 264         if (!dev->file_last) {
 265                 priv->next = NULL;
 266                 priv->prev = NULL;
 267                 dev->file_first = priv;
 268                 dev->file_last = priv;
 269                 /* first opener automatically becomes master */
 270                 priv->master = 1;
 271         } else {
 272                 priv->next = NULL;
 273                 priv->prev = dev->file_last;
 274                 dev->file_last->next = priv;
 275                 dev->file_last = priv;
 276         }
 277         mutex_unlock(&dev->struct_mutex);
 278
 279 #ifdef __alpha__
 280         /*
 281          * Default the hose
 282          */
 283         if (!dev->hose) {
 284                 struct pci_dev *pci_dev;
 285                 pci_dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
 286                 if (pci_dev) {
 287                         dev->hose = pci_dev->sysdata;
 288                         pci_dev_put(pci_dev);
 289                 }
 290                 if (!dev->hose) {
 291                         struct pci_bus *b = pci_bus_b(pci_root_buses.next);
 292                         if (b)
 293                                 dev->hose = b->sysdata;
 294                 }
 295         }
 296 #endif
 297
 298         return 0;
 299       out_free:
 300         drm_free(priv, sizeof(*priv), DRM_MEM_FILES);
 301         filp->private_data = NULL;
 302         return ret;
 303 }
 304
 305 /** No-op. */
 306 int drm_fasync(int fd, struct file *filp, int on)
 307 {
 308         drm_file_t *priv = filp->private_data;
 309         drm_device_t *dev = priv->head->dev;
 310         int retcode;
 311
 312         DRM_DEBUG("fd = %d, device = 0x%lx\n", fd,
 313                   (long)old_encode_dev(priv->head->device));
 314         retcode = fasync_helper(fd, filp, on, &dev->buf_async);
 315         if (retcode < 0)
 316                 return retcode;
 317         return 0;
 318 }
 319 EXPORT_SYMBOL(drm_fasync);
 320
 321 /**
 322  * Release file.
 323  *
 324  * \param inode device inode
 325  * \param filp file pointer.
 326  * \return zero on success or a negative number on failure.
 327  *
 328  * If the hardware lock is held then free it, and take it again for the kernel
 329  * context since it's necessary to reclaim buffers. Unlink the file private
 330  * data from its list and free it. Decreases the open count and if it reaches
 331  * zero calls drm_lastclose().
 332  */
 333 int drm_release(struct inode *inode, struct file *filp)
 334 {
 335         drm_file_t *priv = filp->private_data;
 336         drm_device_t *dev;
 337         int retcode = 0;
 338
 339         lock_kernel();
 340         dev = priv->head->dev;
 341
 342         DRM_DEBUG("open_count = %d\n", dev->open_count);
 343
 344         if (dev->driver->preclose)
 345                 dev->driver->preclose(dev, filp);
 346
 347         /* ========================================================
 348          * Begin inline drm_release
 349          */
 350
 351         DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
 352                   current->pid, (long)old_encode_dev(priv->head->device),
 353                   dev->open_count);
 354
 355         if (priv->lock_count && dev->lock.hw_lock &&
 356             _DRM_LOCK_IS_HELD(dev->lock.hw_lock->lock) &&
 357             dev->lock.filp == filp) {
 358                 DRM_DEBUG("File %p released, freeing lock for context %d\n",
 359                           filp, _DRM_LOCKING_CONTEXT(dev->lock.hw_lock->lock));
 360
 361                 if (dev->driver->reclaim_buffers_locked)
 362                         dev->driver->reclaim_buffers_locked(dev, filp);
 363
 364                 drm_lock_free(dev, &dev->lock.hw_lock->lock,
 365                               _DRM_LOCKING_CONTEXT(dev->lock.hw_lock->lock));
 366
 367                 /* FIXME: may require heavy-handed reset of
 368                    hardware at this point, possibly
 369                    processed via a callback to the X
 370                    server. */
 371         } else if (dev->driver->reclaim_buffers_locked && priv->lock_count
 372                    && dev->lock.hw_lock) {
 373                 /* The lock is required to reclaim buffers */
 374                 DECLARE_WAITQUEUE(entry, current);
 375
 376                 add_wait_queue(&dev->lock.lock_queue, &entry);
 377                 for (;;) {
 378                         __set_current_state(TASK_INTERRUPTIBLE);
 379                         if (!dev->lock.hw_lock) {
 380                                 /* Device has been unregistered */
 381                                 retcode = -EINTR;
 382                                 break;
 383                         }
 384                         if (drm_lock_take(&dev->lock.hw_lock->lock,
 385                                           DRM_KERNEL_CONTEXT)) {
 386                                 dev->lock.filp = filp;
 387                                 dev->lock.lock_time = jiffies;
 388                                 atomic_inc(&dev->counts[_DRM_STAT_LOCKS]);
 389                                 break;  /* Got lock */
 390                         }
 391                         /* Contention */
 392                         schedule();
 393                         if (signal_pending(current)) {
 394                                 retcode = -ERESTARTSYS;
 395                                 break;
 396                         }
 397                 }
 398                 __set_current_state(TASK_RUNNING);
 399                 remove_wait_queue(&dev->lock.lock_queue, &entry);
 400                 if (!retcode) {
 401                         dev->driver->reclaim_buffers_locked(dev, filp);
 402                         drm_lock_free(dev, &dev->lock.hw_lock->lock,
 403                                       DRM_KERNEL_CONTEXT);
 404                 }
 405         }
 406
 407         if (drm_core_check_feature(dev, DRIVER_HAVE_DMA) &&
 408             !dev->driver->reclaim_buffers_locked) {
 409                 dev->driver->reclaim_buffers(dev, filp);
 410         }
 411
 412         drm_fasync(-1, filp, 0);
 413
 414         mutex_lock(&dev->ctxlist_mutex);
 415         if (dev->ctxlist && (!list_empty(&dev->ctxlist->head))) {
 416                 drm_ctx_list_t *pos, *n;
 417
 418                 list_for_each_entry_safe(pos, n, &dev->ctxlist->head, head) {
 419                         if (pos->tag == priv &&
 420                             pos->handle != DRM_KERNEL_CONTEXT) {
 421                                 if (dev->driver->context_dtor)
 422                                         dev->driver->context_dtor(dev,
 423                                                                   pos->handle);
 424
 425                                 drm_ctxbitmap_free(dev, pos->handle);
 426
 427                                 list_del(&pos->head);
 428                                 drm_free(pos, sizeof(*pos), DRM_MEM_CTXLIST);
 429                                 --dev->ctx_count;
 430                         }
 431                 }
 432         }
 433         mutex_unlock(&dev->ctxlist_mutex);
 434
 435         mutex_lock(&dev->struct_mutex);
 436         if (priv->remove_auth_on_close == 1) {
 437                 drm_file_t *temp = dev->file_first;
 438                 while (temp) {
 439                         temp->authenticated = 0;
 440                         temp = temp->next;
 441                 }
 442         }
 443         if (priv->prev) {
 444                 priv->prev->next = priv->next;
 445         } else {
 446                 dev->file_first = priv->next;
 447         }
 448         if (priv->next) {
 449                 priv->next->prev = priv->prev;
 450         } else {
 451                 dev->file_last = priv->prev;
 452         }
 453         mutex_unlock(&dev->struct_mutex);
 454
 455         if (dev->driver->postclose)
 456                 dev->driver->postclose(dev, priv);
 457         drm_free(priv, sizeof(*priv), DRM_MEM_FILES);
 458
 459         /* ========================================================
 460          * End inline drm_release
 461          */
 462
 463         atomic_inc(&dev->counts[_DRM_STAT_CLOSES]);
 464         spin_lock(&dev->count_lock);
 465         if (!--dev->open_count) {
 466                 if (atomic_read(&dev->ioctl_count) || dev->blocked) {
 467                         DRM_ERROR("Device busy: %d %d\n",
 468                                   atomic_read(&dev->ioctl_count), dev->blocked);
 469                         spin_unlock(&dev->count_lock);
 470                         unlock_kernel();
 471                         return -EBUSY;
 472                 }
 473                 spin_unlock(&dev->count_lock);
 474                 unlock_kernel();
 475                 return drm_lastclose(dev);
 476         }
 477         spin_unlock(&dev->count_lock);
 478
 479         unlock_kernel();
 480
 481         return retcode;
 482 }
 483 EXPORT_SYMBOL(drm_release);
 484
 485 /** No-op. */
 486 unsigned int drm_poll(struct file *filp, struct poll_table_struct *wait)
 487 {
 488         return 0;
 489 }
 490 EXPORT_SYMBOL(drm_poll);