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 <linux/poll.h>
  39
  40 static int drm_open_helper(struct inode *inode, struct file *filp,
  41                            drm_device_t * dev);
  42
  43 static int drm_setup(drm_device_t * dev)
  44 {
  45         int i;
  46         int ret;
  47
  48         if (dev->driver->presetup) {
  49                 ret = dev->driver->presetup(dev);
  50                 if (ret != 0)
  51                         return ret;
  52         }
  53
  54         atomic_set(&dev->ioctl_count, 0);
  55         atomic_set(&dev->vma_count, 0);
  56         dev->buf_use = 0;
  57         atomic_set(&dev->buf_alloc, 0);
  58
  59         if (drm_core_check_feature(dev, DRIVER_HAVE_DMA)) {
  60                 i = drm_dma_setup(dev);
  61                 if (i < 0)
  62                         return i;
  63         }
  64
  65         for (i = 0; i < DRM_ARRAY_SIZE(dev->counts); i++)
  66                 atomic_set(&dev->counts[i], 0);
  67
  68         for (i = 0; i < DRM_HASH_SIZE; i++) {
  69                 dev->magiclist[i].head = NULL;
  70                 dev->magiclist[i].tail = NULL;
  71         }
  72
  73         dev->ctxlist = drm_alloc(sizeof(*dev->ctxlist), DRM_MEM_CTXLIST);
  74         if (dev->ctxlist == NULL)
  75                 return -ENOMEM;
  76         memset(dev->ctxlist, 0, sizeof(*dev->ctxlist));
  77         INIT_LIST_HEAD(&dev->ctxlist->head);
  78
  79         dev->vmalist = NULL;
  80         dev->sigdata.lock = dev->lock.hw_lock = NULL;
  81         init_waitqueue_head(&dev->lock.lock_queue);
  82         dev->queue_count = 0;
  83         dev->queue_reserved = 0;
  84         dev->queue_slots = 0;
  85         dev->queuelist = NULL;
  86         dev->irq_enabled = 0;
  87         dev->context_flag = 0;
  88         dev->interrupt_flag = 0;
  89         dev->dma_flag = 0;
  90         dev->last_context = 0;
  91         dev->last_switch = 0;
  92         dev->last_checked = 0;
  93         init_waitqueue_head(&dev->context_wait);
  94         dev->if_version = 0;
  95
  96         dev->ctx_start = 0;
  97         dev->lck_start = 0;
  98
  99         dev->buf_async = NULL;
 100         init_waitqueue_head(&dev->buf_readers);
 101         init_waitqueue_head(&dev->buf_writers);
 102
 103         DRM_DEBUG("\n");
 104
 105         /*
 106          * The kernel's context could be created here, but is now created
 107          * in drm_dma_enqueue.  This is more resource-efficient for
 108          * hardware that does not do DMA, but may mean that
 109          * drm_select_queue fails between the time the interrupt is
 110          * initialized and the time the queues are initialized.
 111          */
 112         if (dev->driver->postsetup)
 113                 dev->driver->postsetup(dev);
 114
 115         return 0;
 116 }
 117
 118 /**
 119  * Open file.
 120  *
 121  * \param inode device inode
 122  * \param filp file pointer.
 123  * \return zero on success or a negative number on failure.
 124  *
 125  * Searches the DRM device with the same minor number, calls open_helper(), and
 126  * increments the device open count. If the open count was previous at zero,
 127  * i.e., it's the first that the device is open, then calls setup().
 128  */
 129 int drm_open(struct inode *inode, struct file *filp)
 130 {
 131         drm_device_t *dev = NULL;
 132         int minor = iminor(inode);
 133         int retcode = 0;
 134
 135         if (!((minor >= 0) && (minor < drm_cards_limit)))
 136                 return -ENODEV;
 137
 138         if (!drm_heads[minor])
 139                 return -ENODEV;
 140
 141         if (!(dev = drm_heads[minor]->dev))
 142                 return -ENODEV;
 143
 144         retcode = drm_open_helper(inode, filp, dev);
 145         if (!retcode) {
 146                 atomic_inc(&dev->counts[_DRM_STAT_OPENS]);
 147                 spin_lock(&dev->count_lock);
 148                 if (!dev->open_count++) {
 149                         spin_unlock(&dev->count_lock);
 150                         return drm_setup(dev);
 151                 }
 152                 spin_unlock(&dev->count_lock);
 153         }
 154
 155         return retcode;
 156 }
 157
 158 EXPORT_SYMBOL(drm_open);
 159
 160 /**
 161  * Release file.
 162  *
 163  * \param inode device inode
 164  * \param filp file pointer.
 165  * \return zero on success or a negative number on failure.
 166  *
 167  * If the hardware lock is held then free it, and take it again for the kernel
 168  * context since it's necessary to reclaim buffers. Unlink the file private
 169  * data from its list and free it. Decreases the open count and if it reaches
 170  * zero calls takedown().
 171  */
 172 int drm_release(struct inode *inode, struct file *filp)
 173 {
 174         drm_file_t *priv = filp->private_data;
 175         drm_device_t *dev;
 176         int retcode = 0;
 177
 178         lock_kernel();
 179         dev = priv->head->dev;
 180
 181         DRM_DEBUG("open_count = %d\n", dev->open_count);
 182
 183         if (dev->driver->prerelease)
 184                 dev->driver->prerelease(dev, filp);
 185
 186         /* ========================================================
 187          * Begin inline drm_release
 188          */
 189
 190         DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
 191                   current->pid, (long)old_encode_dev(priv->head->device),
 192                   dev->open_count);
 193
 194         if (priv->lock_count && dev->lock.hw_lock &&
 195             _DRM_LOCK_IS_HELD(dev->lock.hw_lock->lock) &&
 196             dev->lock.filp == filp) {
 197                 DRM_DEBUG("File %p released, freeing lock for context %d\n",
 198                           filp, _DRM_LOCKING_CONTEXT(dev->lock.hw_lock->lock));
 199
 200                 if (dev->driver->release)
 201                         dev->driver->release(dev, filp);
 202
 203                 drm_lock_free(dev, &dev->lock.hw_lock->lock,
 204                               _DRM_LOCKING_CONTEXT(dev->lock.hw_lock->lock));
 205
 206                 /* FIXME: may require heavy-handed reset of
 207                    hardware at this point, possibly
 208                    processed via a callback to the X
 209                    server. */
 210         } else if (dev->driver->release && priv->lock_count
 211                    && dev->lock.hw_lock) {
 212                 /* The lock is required to reclaim buffers */
 213                 DECLARE_WAITQUEUE(entry, current);
 214
 215                 add_wait_queue(&dev->lock.lock_queue, &entry);
 216                 for (;;) {
 217                         __set_current_state(TASK_INTERRUPTIBLE);
 218                         if (!dev->lock.hw_lock) {
 219                                 /* Device has been unregistered */
 220                                 retcode = -EINTR;
 221                                 break;
 222                         }
 223                         if (drm_lock_take(&dev->lock.hw_lock->lock,
 224                                           DRM_KERNEL_CONTEXT)) {
 225                                 dev->lock.filp = filp;
 226                                 dev->lock.lock_time = jiffies;
 227                                 atomic_inc(&dev->counts[_DRM_STAT_LOCKS]);
 228                                 break;  /* Got lock */
 229                         }
 230                         /* Contention */
 231                         schedule();
 232                         if (signal_pending(current)) {
 233                                 retcode = -ERESTARTSYS;
 234                                 break;
 235                         }
 236                 }
 237                 __set_current_state(TASK_RUNNING);
 238                 remove_wait_queue(&dev->lock.lock_queue, &entry);
 239                 if (!retcode) {
 240                         if (dev->driver->release)
 241                                 dev->driver->release(dev, filp);
 242                         drm_lock_free(dev, &dev->lock.hw_lock->lock,
 243                                       DRM_KERNEL_CONTEXT);
 244                 }
 245         }
 246
 247         if (drm_core_check_feature(dev, DRIVER_HAVE_DMA)
 248             && !dev->driver->release) {
 249                 dev->driver->reclaim_buffers(dev, filp);
 250         }
 251
 252         drm_fasync(-1, filp, 0);
 253
 254         down(&dev->ctxlist_sem);
 255         if (dev->ctxlist && (!list_empty(&dev->ctxlist->head))) {
 256                 drm_ctx_list_t *pos, *n;
 257
 258                 list_for_each_entry_safe(pos, n, &dev->ctxlist->head, head) {
 259                         if (pos->tag == priv &&
 260                             pos->handle != DRM_KERNEL_CONTEXT) {
 261                                 if (dev->driver->context_dtor)
 262                                         dev->driver->context_dtor(dev,
 263                                                                   pos->handle);
 264
 265                                 drm_ctxbitmap_free(dev, pos->handle);
 266
 267                                 list_del(&pos->head);
 268                                 drm_free(pos, sizeof(*pos), DRM_MEM_CTXLIST);
 269                                 --dev->ctx_count;
 270                         }
 271                 }
 272         }
 273         up(&dev->ctxlist_sem);
 274
 275         down(&dev->struct_sem);
 276         if (priv->remove_auth_on_close == 1) {
 277                 drm_file_t *temp = dev->file_first;
 278                 while (temp) {
 279                         temp->authenticated = 0;
 280                         temp = temp->next;
 281                 }
 282         }
 283         if (priv->prev) {
 284                 priv->prev->next = priv->next;
 285         } else {
 286                 dev->file_first = priv->next;
 287         }
 288         if (priv->next) {
 289                 priv->next->prev = priv->prev;
 290         } else {
 291                 dev->file_last = priv->prev;
 292         }
 293         up(&dev->struct_sem);
 294
 295         if (dev->driver->free_filp_priv)
 296                 dev->driver->free_filp_priv(dev, priv);
 297
 298         drm_free(priv, sizeof(*priv), DRM_MEM_FILES);
 299
 300         /* ========================================================
 301          * End inline drm_release
 302          */
 303
 304         atomic_inc(&dev->counts[_DRM_STAT_CLOSES]);
 305         spin_lock(&dev->count_lock);
 306         if (!--dev->open_count) {
 307                 if (atomic_read(&dev->ioctl_count) || dev->blocked) {
 308                         DRM_ERROR("Device busy: %d %d\n",
 309                                   atomic_read(&dev->ioctl_count), dev->blocked);
 310                         spin_unlock(&dev->count_lock);
 311                         unlock_kernel();
 312                         return -EBUSY;
 313                 }
 314                 spin_unlock(&dev->count_lock);
 315                 unlock_kernel();
 316                 return drm_takedown(dev);
 317         }
 318         spin_unlock(&dev->count_lock);
 319
 320         unlock_kernel();
 321
 322         return retcode;
 323 }
 324
 325 EXPORT_SYMBOL(drm_release);
 326
 327 /**
 328  * Called whenever a process opens /dev/drm.
 329  *
 330  * \param inode device inode.
 331  * \param filp file pointer.
 332  * \param dev device.
 333  * \return zero on success or a negative number on failure.
 334  *
 335  * Creates and initializes a drm_file structure for the file private data in \p
 336  * filp and add it into the double linked list in \p dev.
 337  */
 338 static int drm_open_helper(struct inode *inode, struct file *filp,
 339                            drm_device_t * dev)
 340 {
 341         int minor = iminor(inode);
 342         drm_file_t *priv;
 343         int ret;
 344
 345         if (filp->f_flags & O_EXCL)
 346                 return -EBUSY;  /* No exclusive opens */
 347         if (!drm_cpu_valid())
 348                 return -EINVAL;
 349
 350         DRM_DEBUG("pid = %d, minor = %d\n", current->pid, minor);
 351
 352         priv = drm_alloc(sizeof(*priv), DRM_MEM_FILES);
 353         if (!priv)
 354                 return -ENOMEM;
 355
 356         memset(priv, 0, sizeof(*priv));
 357         filp->private_data = priv;
 358         priv->uid = current->euid;
 359         priv->pid = current->pid;
 360         priv->minor = minor;
 361         priv->head = drm_heads[minor];
 362         priv->ioctl_count = 0;
 363         priv->authenticated = capable(CAP_SYS_ADMIN);
 364         priv->lock_count = 0;
 365
 366         if (dev->driver->open_helper) {
 367                 ret = dev->driver->open_helper(dev, priv);
 368                 if (ret < 0)
 369                         goto out_free;
 370         }
 371
 372         down(&dev->struct_sem);
 373         if (!dev->file_last) {
 374                 priv->next = NULL;
 375                 priv->prev = NULL;
 376                 dev->file_first = priv;
 377                 dev->file_last = priv;
 378         } else {
 379                 priv->next = NULL;
 380                 priv->prev = dev->file_last;
 381                 dev->file_last->next = priv;
 382                 dev->file_last = priv;
 383         }
 384         up(&dev->struct_sem);
 385
 386 #ifdef __alpha__
 387         /*
 388          * Default the hose
 389          */
 390         if (!dev->hose) {
 391                 struct pci_dev *pci_dev;
 392                 pci_dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
 393                 if (pci_dev) {
 394                         dev->hose = pci_dev->sysdata;
 395                         pci_dev_put(pci_dev);
 396                 }
 397                 if (!dev->hose) {
 398                         struct pci_bus *b = pci_bus_b(pci_root_buses.next);
 399                         if (b)
 400                                 dev->hose = b->sysdata;
 401                 }
 402         }
 403 #endif
 404
 405         return 0;
 406       out_free:
 407         drm_free(priv, sizeof(*priv), DRM_MEM_FILES);
 408         filp->private_data = NULL;
 409         return ret;
 410 }
 411
 412 /** No-op. */
 413 int drm_flush(struct file *filp)
 414 {
 415         drm_file_t *priv = filp->private_data;
 416         drm_device_t *dev = priv->head->dev;
 417
 418         DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
 419                   current->pid, (long)old_encode_dev(priv->head->device),
 420                   dev->open_count);
 421         return 0;
 422 }
 423
 424 EXPORT_SYMBOL(drm_flush);
 425
 426 /** No-op. */
 427 int drm_fasync(int fd, struct file *filp, int on)
 428 {
 429         drm_file_t *priv = filp->private_data;
 430         drm_device_t *dev = priv->head->dev;
 431         int retcode;
 432
 433         DRM_DEBUG("fd = %d, device = 0x%lx\n", fd,
 434                   (long)old_encode_dev(priv->head->device));
 435         retcode = fasync_helper(fd, filp, on, &dev->buf_async);
 436         if (retcode < 0)
 437                 return retcode;
 438         return 0;
 439 }
 440
 441 EXPORT_SYMBOL(drm_fasync);
 442
 443 /** No-op. */
 444 unsigned int drm_poll(struct file *filp, struct poll_table_struct *wait)
 445 {
 446         return 0;
 447 }
 448
 449 EXPORT_SYMBOL(drm_poll);