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_rp = dev->buf;
 100         dev->buf_wp = dev->buf;
 101         dev->buf_end = dev->buf + DRM_BSZ;
 102         dev->buf_async = NULL;
 103         init_waitqueue_head(&dev->buf_readers);
 104         init_waitqueue_head(&dev->buf_writers);
 105
 106         DRM_DEBUG("\n");
 107
 108         /*
 109          * The kernel's context could be created here, but is now created
 110          * in drm_dma_enqueue.  This is more resource-efficient for
 111          * hardware that does not do DMA, but may mean that
 112          * drm_select_queue fails between the time the interrupt is
 113          * initialized and the time the queues are initialized.
 114          */
 115         if (dev->driver->postsetup)
 116                 dev->driver->postsetup(dev);
 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
 161 EXPORT_SYMBOL(drm_open);
 162
 163 /**
 164  * Release file.
 165  *
 166  * \param inode device inode
 167  * \param filp file pointer.
 168  * \return zero on success or a negative number on failure.
 169  *
 170  * If the hardware lock is held then free it, and take it again for the kernel
 171  * context since it's necessary to reclaim buffers. Unlink the file private
 172  * data from its list and free it. Decreases the open count and if it reaches
 173  * zero calls takedown().
 174  */
 175 int drm_release(struct inode *inode, struct file *filp)
 176 {
 177         drm_file_t *priv = filp->private_data;
 178         drm_device_t *dev;
 179         int retcode = 0;
 180
 181         lock_kernel();
 182         dev = priv->head->dev;
 183
 184         DRM_DEBUG("open_count = %d\n", dev->open_count);
 185
 186         if (dev->driver->prerelease)
 187                 dev->driver->prerelease(dev, filp);
 188
 189         /* ========================================================
 190          * Begin inline drm_release
 191          */
 192
 193         DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
 194                   current->pid, (long)old_encode_dev(priv->head->device),
 195                   dev->open_count);
 196
 197         if (priv->lock_count && dev->lock.hw_lock &&
 198             _DRM_LOCK_IS_HELD(dev->lock.hw_lock->lock) &&
 199             dev->lock.filp == filp) {
 200                 DRM_DEBUG("File %p released, freeing lock for context %d\n",
 201                           filp, _DRM_LOCKING_CONTEXT(dev->lock.hw_lock->lock));
 202
 203                 if (dev->driver->release)
 204                         dev->driver->release(dev, filp);
 205
 206                 drm_lock_free(dev, &dev->lock.hw_lock->lock,
 207                               _DRM_LOCKING_CONTEXT(dev->lock.hw_lock->lock));
 208
 209                 /* FIXME: may require heavy-handed reset of
 210                    hardware at this point, possibly
 211                    processed via a callback to the X
 212                    server. */
 213         } else if (dev->driver->release && priv->lock_count
 214                    && dev->lock.hw_lock) {
 215                 /* The lock is required to reclaim buffers */
 216                 DECLARE_WAITQUEUE(entry, current);
 217
 218                 add_wait_queue(&dev->lock.lock_queue, &entry);
 219                 for (;;) {
 220                         __set_current_state(TASK_INTERRUPTIBLE);
 221                         if (!dev->lock.hw_lock) {
 222                                 /* Device has been unregistered */
 223                                 retcode = -EINTR;
 224                                 break;
 225                         }
 226                         if (drm_lock_take(&dev->lock.hw_lock->lock,
 227                                           DRM_KERNEL_CONTEXT)) {
 228                                 dev->lock.filp = filp;
 229                                 dev->lock.lock_time = jiffies;
 230                                 atomic_inc(&dev->counts[_DRM_STAT_LOCKS]);
 231                                 break;  /* Got lock */
 232                         }
 233                         /* Contention */
 234                         schedule();
 235                         if (signal_pending(current)) {
 236                                 retcode = -ERESTARTSYS;
 237                                 break;
 238                         }
 239                 }
 240                 __set_current_state(TASK_RUNNING);
 241                 remove_wait_queue(&dev->lock.lock_queue, &entry);
 242                 if (!retcode) {
 243                         if (dev->driver->release)
 244                                 dev->driver->release(dev, filp);
 245                         drm_lock_free(dev, &dev->lock.hw_lock->lock,
 246                                       DRM_KERNEL_CONTEXT);
 247                 }
 248         }
 249
 250         if (drm_core_check_feature(dev, DRIVER_HAVE_DMA)
 251             && !dev->driver->release) {
 252                 dev->driver->reclaim_buffers(dev, filp);
 253         }
 254
 255         drm_fasync(-1, filp, 0);
 256
 257         down(&dev->ctxlist_sem);
 258         if (dev->ctxlist && (!list_empty(&dev->ctxlist->head))) {
 259                 drm_ctx_list_t *pos, *n;
 260
 261                 list_for_each_entry_safe(pos, n, &dev->ctxlist->head, head) {
 262                         if (pos->tag == priv &&
 263                             pos->handle != DRM_KERNEL_CONTEXT) {
 264                                 if (dev->driver->context_dtor)
 265                                         dev->driver->context_dtor(dev,
 266                                                                   pos->handle);
 267
 268                                 drm_ctxbitmap_free(dev, pos->handle);
 269
 270                                 list_del(&pos->head);
 271                                 drm_free(pos, sizeof(*pos), DRM_MEM_CTXLIST);
 272                                 --dev->ctx_count;
 273                         }
 274                 }
 275         }
 276         up(&dev->ctxlist_sem);
 277
 278         down(&dev->struct_sem);
 279         if (priv->remove_auth_on_close == 1) {
 280                 drm_file_t *temp = dev->file_first;
 281                 while (temp) {
 282                         temp->authenticated = 0;
 283                         temp = temp->next;
 284                 }
 285         }
 286         if (priv->prev) {
 287                 priv->prev->next = priv->next;
 288         } else {
 289                 dev->file_first = priv->next;
 290         }
 291         if (priv->next) {
 292                 priv->next->prev = priv->prev;
 293         } else {
 294                 dev->file_last = priv->prev;
 295         }
 296         up(&dev->struct_sem);
 297
 298         if (dev->driver->free_filp_priv)
 299                 dev->driver->free_filp_priv(dev, priv);
 300
 301         drm_free(priv, sizeof(*priv), DRM_MEM_FILES);
 302
 303         /* ========================================================
 304          * End inline drm_release
 305          */
 306
 307         atomic_inc(&dev->counts[_DRM_STAT_CLOSES]);
 308         spin_lock(&dev->count_lock);
 309         if (!--dev->open_count) {
 310                 if (atomic_read(&dev->ioctl_count) || dev->blocked) {
 311                         DRM_ERROR("Device busy: %d %d\n",
 312                                   atomic_read(&dev->ioctl_count), dev->blocked);
 313                         spin_unlock(&dev->count_lock);
 314                         unlock_kernel();
 315                         return -EBUSY;
 316                 }
 317                 spin_unlock(&dev->count_lock);
 318                 unlock_kernel();
 319                 return drm_takedown(dev);
 320         }
 321         spin_unlock(&dev->count_lock);
 322
 323         unlock_kernel();
 324
 325         return retcode;
 326 }
 327
 328 EXPORT_SYMBOL(drm_release);
 329
 330 /**
 331  * Called whenever a process opens /dev/drm.
 332  *
 333  * \param inode device inode.
 334  * \param filp file pointer.
 335  * \param dev device.
 336  * \return zero on success or a negative number on failure.
 337  *
 338  * Creates and initializes a drm_file structure for the file private data in \p
 339  * filp and add it into the double linked list in \p dev.
 340  */
 341 static int drm_open_helper(struct inode *inode, struct file *filp,
 342                            drm_device_t * dev)
 343 {
 344         int minor = iminor(inode);
 345         drm_file_t *priv;
 346         int ret;
 347
 348         if (filp->f_flags & O_EXCL)
 349                 return -EBUSY;  /* No exclusive opens */
 350         if (!drm_cpu_valid())
 351                 return -EINVAL;
 352
 353         DRM_DEBUG("pid = %d, minor = %d\n", current->pid, minor);
 354
 355         priv = drm_alloc(sizeof(*priv), DRM_MEM_FILES);
 356         if (!priv)
 357                 return -ENOMEM;
 358
 359         memset(priv, 0, sizeof(*priv));
 360         filp->private_data = priv;
 361         priv->uid = current->euid;
 362         priv->pid = current->pid;
 363         priv->minor = minor;
 364         priv->head = drm_heads[minor];
 365         priv->ioctl_count = 0;
 366         priv->authenticated = capable(CAP_SYS_ADMIN);
 367         priv->lock_count = 0;
 368
 369         if (dev->driver->open_helper) {
 370                 ret = dev->driver->open_helper(dev, priv);
 371                 if (ret < 0)
 372                         goto out_free;
 373         }
 374
 375         down(&dev->struct_sem);
 376         if (!dev->file_last) {
 377                 priv->next = NULL;
 378                 priv->prev = NULL;
 379                 dev->file_first = priv;
 380                 dev->file_last = priv;
 381         } else {
 382                 priv->next = NULL;
 383                 priv->prev = dev->file_last;
 384                 dev->file_last->next = priv;
 385                 dev->file_last = priv;
 386         }
 387         up(&dev->struct_sem);
 388
 389 #ifdef __alpha__
 390         /*
 391          * Default the hose
 392          */
 393         if (!dev->hose) {
 394                 struct pci_dev *pci_dev;
 395                 pci_dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
 396                 if (pci_dev) {
 397                         dev->hose = pci_dev->sysdata;
 398                         pci_dev_put(pci_dev);
 399                 }
 400                 if (!dev->hose) {
 401                         struct pci_bus *b = pci_bus_b(pci_root_buses.next);
 402                         if (b)
 403                                 dev->hose = b->sysdata;
 404                 }
 405         }
 406 #endif
 407
 408         return 0;
 409       out_free:
 410         drm_free(priv, sizeof(*priv), DRM_MEM_FILES);
 411         filp->private_data = NULL;
 412         return ret;
 413 }
 414
 415 /** No-op. */
 416 int drm_flush(struct file *filp)
 417 {
 418         drm_file_t *priv = filp->private_data;
 419         drm_device_t *dev = priv->head->dev;
 420
 421         DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
 422                   current->pid, (long)old_encode_dev(priv->head->device),
 423                   dev->open_count);
 424         return 0;
 425 }
 426
 427 EXPORT_SYMBOL(drm_flush);
 428
 429 /** No-op. */
 430 int drm_fasync(int fd, struct file *filp, int on)
 431 {
 432         drm_file_t *priv = filp->private_data;
 433         drm_device_t *dev = priv->head->dev;
 434         int retcode;
 435
 436         DRM_DEBUG("fd = %d, device = 0x%lx\n", fd,
 437                   (long)old_encode_dev(priv->head->device));
 438         retcode = fasync_helper(fd, filp, on, &dev->buf_async);
 439         if (retcode < 0)
 440                 return retcode;
 441         return 0;
 442 }
 443
 444 EXPORT_SYMBOL(drm_fasync);
 445
 446 /** No-op. */
 447 unsigned int drm_poll(struct file *filp, struct poll_table_struct *wait)
 448 {
 449         return 0;
 450 }
 451
 452 EXPORT_SYMBOL(drm_poll);