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         dev->magicfree.next = NULL;
  57
  58         /* prebuild the SAREA */
  59         i = drm_addmap(dev, 0, SAREA_MAX, _DRM_SHM, _DRM_CONTAINS_LOCK, &map);
  60         if (i != 0)
  61                 return i;
  62
  63         atomic_set(&dev->ioctl_count, 0);
  64         atomic_set(&dev->vma_count, 0);
  65         dev->buf_use = 0;
  66         atomic_set(&dev->buf_alloc, 0);
  67
  68         if (drm_core_check_feature(dev, DRIVER_HAVE_DMA)) {
  69                 i = drm_dma_setup(dev);
  70                 if (i < 0)
  71                         return i;
  72         }
  73
  74         for (i = 0; i < ARRAY_SIZE(dev->counts); i++)
  75                 atomic_set(&dev->counts[i], 0);
  76
  77         drm_ht_create(&dev->magiclist, DRM_MAGIC_HASH_ORDER);
  78         INIT_LIST_HEAD(&dev->magicfree);
  79
  80         dev->ctxlist = drm_alloc(sizeof(*dev->ctxlist), DRM_MEM_CTXLIST);
  81         if (dev->ctxlist == NULL)
  82                 return -ENOMEM;
  83         memset(dev->ctxlist, 0, sizeof(*dev->ctxlist));
  84         INIT_LIST_HEAD(&dev->ctxlist->head);
  85
  86         dev->vmalist = NULL;
  87         dev->sigdata.lock = dev->lock.hw_lock = NULL;
  88         init_waitqueue_head(&dev->lock.lock_queue);
  89         dev->queue_count = 0;
  90         dev->queue_reserved = 0;
  91         dev->queue_slots = 0;
  92         dev->queuelist = NULL;
  93         dev->irq_enabled = 0;
  94         dev->context_flag = 0;
  95         dev->interrupt_flag = 0;
  96         dev->dma_flag = 0;
  97         dev->last_context = 0;
  98         dev->last_switch = 0;
  99         dev->last_checked = 0;
 100         init_waitqueue_head(&dev->context_wait);
 101         dev->if_version = 0;
 102
 103         dev->ctx_start = 0;
 104         dev->lck_start = 0;
 105
 106         dev->buf_async = NULL;
 107         init_waitqueue_head(&dev->buf_readers);
 108         init_waitqueue_head(&dev->buf_writers);
 109
 110         DRM_DEBUG("\n");
 111
 112         /*
 113          * The kernel's context could be created here, but is now created
 114          * in drm_dma_enqueue.  This is more resource-efficient for
 115          * hardware that does not do DMA, but may mean that
 116          * drm_select_queue fails between the time the interrupt is
 117          * initialized and the time the queues are initialized.
 118          */
 119
 120         return 0;
 121 }
 122
 123 /**
 124  * Open file.
 125  *
 126  * \param inode device inode
 127  * \param filp file pointer.
 128  * \return zero on success or a negative number on failure.
 129  *
 130  * Searches the DRM device with the same minor number, calls open_helper(), and
 131  * increments the device open count. If the open count was previous at zero,
 132  * i.e., it's the first that the device is open, then calls setup().
 133  */
 134 int drm_open(struct inode *inode, struct file *filp)
 135 {
 136         drm_device_t *dev = NULL;
 137         int minor = iminor(inode);
 138         int retcode = 0;
 139
 140         if (!((minor >= 0) && (minor < drm_cards_limit)))
 141                 return -ENODEV;
 142
 143         if (!drm_heads[minor])
 144                 return -ENODEV;
 145
 146         if (!(dev = drm_heads[minor]->dev))
 147                 return -ENODEV;
 148
 149         retcode = drm_open_helper(inode, filp, dev);
 150         if (!retcode) {
 151                 atomic_inc(&dev->counts[_DRM_STAT_OPENS]);
 152                 spin_lock(&dev->count_lock);
 153                 if (!dev->open_count++) {
 154                         spin_unlock(&dev->count_lock);
 155                         return drm_setup(dev);
 156                 }
 157                 spin_unlock(&dev->count_lock);
 158         }
 159
 160         return retcode;
 161 }
 162 EXPORT_SYMBOL(drm_open);
 163
 164 /**
 165  * File \c open operation.
 166  *
 167  * \param inode device inode.
 168  * \param filp file pointer.
 169  *
 170  * Puts the dev->fops corresponding to the device minor number into
 171  * \p filp, call the \c open method, and restore the file operations.
 172  */
 173 int drm_stub_open(struct inode *inode, struct file *filp)
 174 {
 175         drm_device_t *dev = NULL;
 176         int minor = iminor(inode);
 177         int err = -ENODEV;
 178         const struct file_operations *old_fops;
 179
 180         DRM_DEBUG("\n");
 181
 182         if (!((minor >= 0) && (minor < drm_cards_limit)))
 183                 return -ENODEV;
 184
 185         if (!drm_heads[minor])
 186                 return -ENODEV;
 187
 188         if (!(dev = drm_heads[minor]->dev))
 189                 return -ENODEV;
 190
 191         old_fops = filp->f_op;
 192         filp->f_op = fops_get(&dev->driver->fops);
 193         if (filp->f_op->open && (err = filp->f_op->open(inode, filp))) {
 194                 fops_put(filp->f_op);
 195                 filp->f_op = fops_get(old_fops);
 196         }
 197         fops_put(old_fops);
 198
 199         return err;
 200 }
 201
 202 /**
 203  * Check whether DRI will run on this CPU.
 204  *
 205  * \return non-zero if the DRI will run on this CPU, or zero otherwise.
 206  */
 207 static int drm_cpu_valid(void)
 208 {
 209 #if defined(__i386__)
 210         if (boot_cpu_data.x86 == 3)
 211                 return 0;       /* No cmpxchg on a 386 */
 212 #endif
 213 #if defined(__sparc__) && !defined(__sparc_v9__)
 214         return 0;               /* No cmpxchg before v9 sparc. */
 215 #endif
 216         return 1;
 217 }
 218
 219 /**
 220  * Called whenever a process opens /dev/drm.
 221  *
 222  * \param inode device inode.
 223  * \param filp file pointer.
 224  * \param dev device.
 225  * \return zero on success or a negative number on failure.
 226  *
 227  * Creates and initializes a drm_file structure for the file private data in \p
 228  * filp and add it into the double linked list in \p dev.
 229  */
 230 static int drm_open_helper(struct inode *inode, struct file *filp,
 231                            drm_device_t * dev)
 232 {
 233         int minor = iminor(inode);
 234         drm_file_t *priv;
 235         int ret;
 236
 237         if (filp->f_flags & O_EXCL)
 238                 return -EBUSY;  /* No exclusive opens */
 239         if (!drm_cpu_valid())
 240                 return -EINVAL;
 241
 242         DRM_DEBUG("pid = %d, minor = %d\n", current->pid, minor);
 243
 244         priv = drm_alloc(sizeof(*priv), DRM_MEM_FILES);
 245         if (!priv)
 246                 return -ENOMEM;
 247
 248         memset(priv, 0, sizeof(*priv));
 249         filp->private_data = priv;
 250         priv->uid = current->euid;
 251         priv->pid = current->pid;
 252         priv->minor = minor;
 253         priv->head = drm_heads[minor];
 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         if (dev->driver->open) {
 260                 ret = dev->driver->open(dev, priv);
 261                 if (ret < 0)
 262                         goto out_free;
 263         }
 264
 265         mutex_lock(&dev->struct_mutex);
 266         if (!dev->file_last) {
 267                 priv->next = NULL;
 268                 priv->prev = NULL;
 269                 dev->file_first = priv;
 270                 dev->file_last = priv;
 271                 /* first opener automatically becomes master */
 272                 priv->master = 1;
 273         } else {
 274                 priv->next = NULL;
 275                 priv->prev = dev->file_last;
 276                 dev->file_last->next = priv;
 277                 dev->file_last = priv;
 278         }
 279         mutex_unlock(&dev->struct_mutex);
 280
 281 #ifdef __alpha__
 282         /*
 283          * Default the hose
 284          */
 285         if (!dev->hose) {
 286                 struct pci_dev *pci_dev;
 287                 pci_dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
 288                 if (pci_dev) {
 289                         dev->hose = pci_dev->sysdata;
 290                         pci_dev_put(pci_dev);
 291                 }
 292                 if (!dev->hose) {
 293                         struct pci_bus *b = pci_bus_b(pci_root_buses.next);
 294                         if (b)
 295                                 dev->hose = b->sysdata;
 296                 }
 297         }
 298 #endif
 299
 300         return 0;
 301       out_free:
 302         drm_free(priv, sizeof(*priv), DRM_MEM_FILES);
 303         filp->private_data = NULL;
 304         return ret;
 305 }
 306
 307 /** No-op. */
 308 int drm_fasync(int fd, struct file *filp, int on)
 309 {
 310         drm_file_t *priv = filp->private_data;
 311         drm_device_t *dev = priv->head->dev;
 312         int retcode;
 313
 314         DRM_DEBUG("fd = %d, device = 0x%lx\n", fd,
 315                   (long)old_encode_dev(priv->head->device));
 316         retcode = fasync_helper(fd, filp, on, &dev->buf_async);
 317         if (retcode < 0)
 318                 return retcode;
 319         return 0;
 320 }
 321 EXPORT_SYMBOL(drm_fasync);
 322
 323 /**
 324  * Release file.
 325  *
 326  * \param inode device inode
 327  * \param filp file pointer.
 328  * \return zero on success or a negative number on failure.
 329  *
 330  * If the hardware lock is held then free it, and take it again for the kernel
 331  * context since it's necessary to reclaim buffers. Unlink the file private
 332  * data from its list and free it. Decreases the open count and if it reaches
 333  * zero calls drm_lastclose().
 334  */
 335 int drm_release(struct inode *inode, struct file *filp)
 336 {
 337         drm_file_t *priv = filp->private_data;
 338         drm_device_t *dev;
 339         int retcode = 0;
 340
 341         lock_kernel();
 342         dev = priv->head->dev;
 343
 344         DRM_DEBUG("open_count = %d\n", dev->open_count);
 345
 346         if (dev->driver->preclose)
 347                 dev->driver->preclose(dev, filp);
 348
 349         /* ========================================================
 350          * Begin inline drm_release
 351          */
 352
 353         DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
 354                   current->pid, (long)old_encode_dev(priv->head->device),
 355                   dev->open_count);
 356
 357         if (priv->lock_count && dev->lock.hw_lock &&
 358             _DRM_LOCK_IS_HELD(dev->lock.hw_lock->lock) &&
 359             dev->lock.filp == filp) {
 360                 DRM_DEBUG("File %p released, freeing lock for context %d\n",
 361                           filp, _DRM_LOCKING_CONTEXT(dev->lock.hw_lock->lock));
 362
 363                 if (dev->driver->reclaim_buffers_locked)
 364                         dev->driver->reclaim_buffers_locked(dev, filp);
 365
 366                 drm_lock_free(dev, &dev->lock.hw_lock->lock,
 367                               _DRM_LOCKING_CONTEXT(dev->lock.hw_lock->lock));
 368
 369                 /* FIXME: may require heavy-handed reset of
 370                    hardware at this point, possibly
 371                    processed via a callback to the X
 372                    server. */
 373         } else if (dev->driver->reclaim_buffers_locked && priv->lock_count
 374                    && dev->lock.hw_lock) {
 375                 /* The lock is required to reclaim buffers */
 376                 DECLARE_WAITQUEUE(entry, current);
 377
 378                 add_wait_queue(&dev->lock.lock_queue, &entry);
 379                 for (;;) {
 380                         __set_current_state(TASK_INTERRUPTIBLE);
 381                         if (!dev->lock.hw_lock) {
 382                                 /* Device has been unregistered */
 383                                 retcode = -EINTR;
 384                                 break;
 385                         }
 386                         if (drm_lock_take(&dev->lock.hw_lock->lock,
 387                                           DRM_KERNEL_CONTEXT)) {
 388                                 dev->lock.filp = filp;
 389                                 dev->lock.lock_time = jiffies;
 390                                 atomic_inc(&dev->counts[_DRM_STAT_LOCKS]);
 391                                 break;  /* Got lock */
 392                         }
 393                         /* Contention */
 394                         schedule();
 395                         if (signal_pending(current)) {
 396                                 retcode = -ERESTARTSYS;
 397                                 break;
 398                         }
 399                 }
 400                 __set_current_state(TASK_RUNNING);
 401                 remove_wait_queue(&dev->lock.lock_queue, &entry);
 402                 if (!retcode) {
 403                         dev->driver->reclaim_buffers_locked(dev, filp);
 404                         drm_lock_free(dev, &dev->lock.hw_lock->lock,
 405                                       DRM_KERNEL_CONTEXT);
 406                 }
 407         }
 408
 409         if (drm_core_check_feature(dev, DRIVER_HAVE_DMA) &&
 410             !dev->driver->reclaim_buffers_locked) {
 411                 dev->driver->reclaim_buffers(dev, filp);
 412         }
 413
 414         drm_fasync(-1, filp, 0);
 415
 416         mutex_lock(&dev->ctxlist_mutex);
 417         if (dev->ctxlist && (!list_empty(&dev->ctxlist->head))) {
 418                 drm_ctx_list_t *pos, *n;
 419
 420                 list_for_each_entry_safe(pos, n, &dev->ctxlist->head, head) {
 421                         if (pos->tag == priv &&
 422                             pos->handle != DRM_KERNEL_CONTEXT) {
 423                                 if (dev->driver->context_dtor)
 424                                         dev->driver->context_dtor(dev,
 425                                                                   pos->handle);
 426
 427                                 drm_ctxbitmap_free(dev, pos->handle);
 428
 429                                 list_del(&pos->head);
 430                                 drm_free(pos, sizeof(*pos), DRM_MEM_CTXLIST);
 431                                 --dev->ctx_count;
 432                         }
 433                 }
 434         }
 435         mutex_unlock(&dev->ctxlist_mutex);
 436
 437         mutex_lock(&dev->struct_mutex);
 438         if (priv->remove_auth_on_close == 1) {
 439                 drm_file_t *temp = dev->file_first;
 440                 while (temp) {
 441                         temp->authenticated = 0;
 442                         temp = temp->next;
 443                 }
 444         }
 445         if (priv->prev) {
 446                 priv->prev->next = priv->next;
 447         } else {
 448                 dev->file_first = priv->next;
 449         }
 450         if (priv->next) {
 451                 priv->next->prev = priv->prev;
 452         } else {
 453                 dev->file_last = priv->prev;
 454         }
 455         mutex_unlock(&dev->struct_mutex);
 456
 457         if (dev->driver->postclose)
 458                 dev->driver->postclose(dev, priv);
 459         drm_free(priv, sizeof(*priv), DRM_MEM_FILES);
 460
 461         /* ========================================================
 462          * End inline drm_release
 463          */
 464
 465         atomic_inc(&dev->counts[_DRM_STAT_CLOSES]);
 466         spin_lock(&dev->count_lock);
 467         if (!--dev->open_count) {
 468                 if (atomic_read(&dev->ioctl_count) || dev->blocked) {
 469                         DRM_ERROR("Device busy: %d %d\n",
 470                                   atomic_read(&dev->ioctl_count), dev->blocked);
 471                         spin_unlock(&dev->count_lock);
 472                         unlock_kernel();
 473                         return -EBUSY;
 474                 }
 475                 spin_unlock(&dev->count_lock);
 476                 unlock_kernel();
 477                 return drm_lastclose(dev);
 478         }
 479         spin_unlock(&dev->count_lock);
 480
 481         unlock_kernel();
 482
 483         return retcode;
 484 }
 485 EXPORT_SYMBOL(drm_release);
 486
 487 /** No-op. */
 488 unsigned int drm_poll(struct file *filp, struct poll_table_struct *wait)
 489 {
 490         return 0;
 491 }
 492 EXPORT_SYMBOL(drm_poll);