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   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->firstopen) {
  49                 ret = dev->driver->firstopen(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
 113         return 0;
 114 }
 115
 116 /**
 117  * Open file.
 118  *
 119  * \param inode device inode
 120  * \param filp file pointer.
 121  * \return zero on success or a negative number on failure.
 122  *
 123  * Searches the DRM device with the same minor number, calls open_helper(), and
 124  * increments the device open count. If the open count was previous at zero,
 125  * i.e., it's the first that the device is open, then calls setup().
 126  */
 127 int drm_open(struct inode *inode, struct file *filp)
 128 {
 129         drm_device_t *dev = NULL;
 130         int minor = iminor(inode);
 131         int retcode = 0;
 132
 133         if (!((minor >= 0) && (minor < drm_cards_limit)))
 134                 return -ENODEV;
 135
 136         if (!drm_heads[minor])
 137                 return -ENODEV;
 138
 139         if (!(dev = drm_heads[minor]->dev))
 140                 return -ENODEV;
 141
 142         retcode = drm_open_helper(inode, filp, dev);
 143         if (!retcode) {
 144                 atomic_inc(&dev->counts[_DRM_STAT_OPENS]);
 145                 spin_lock(&dev->count_lock);
 146                 if (!dev->open_count++) {
 147                         spin_unlock(&dev->count_lock);
 148                         return drm_setup(dev);
 149                 }
 150                 spin_unlock(&dev->count_lock);
 151         }
 152
 153         return retcode;
 154 }
 155
 156 EXPORT_SYMBOL(drm_open);
 157
 158 /**
 159  * Release file.
 160  *
 161  * \param inode device inode
 162  * \param filp file pointer.
 163  * \return zero on success or a negative number on failure.
 164  *
 165  * If the hardware lock is held then free it, and take it again for the kernel
 166  * context since it's necessary to reclaim buffers. Unlink the file private
 167  * data from its list and free it. Decreases the open count and if it reaches
 168  * zero calls drm_lastclose().
 169  */
 170 int drm_release(struct inode *inode, struct file *filp)
 171 {
 172         drm_file_t *priv = filp->private_data;
 173         drm_device_t *dev;
 174         int retcode = 0;
 175
 176         lock_kernel();
 177         dev = priv->head->dev;
 178
 179         DRM_DEBUG("open_count = %d\n", dev->open_count);
 180
 181         if (dev->driver->preclose)
 182                 dev->driver->preclose(dev, filp);
 183
 184         /* ========================================================
 185          * Begin inline drm_release
 186          */
 187
 188         DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
 189                   current->pid, (long)old_encode_dev(priv->head->device),
 190                   dev->open_count);
 191
 192         if (priv->lock_count && dev->lock.hw_lock &&
 193             _DRM_LOCK_IS_HELD(dev->lock.hw_lock->lock) &&
 194             dev->lock.filp == filp) {
 195                 DRM_DEBUG("File %p released, freeing lock for context %d\n",
 196                           filp, _DRM_LOCKING_CONTEXT(dev->lock.hw_lock->lock));
 197
 198                 if (dev->driver->reclaim_buffers_locked)
 199                         dev->driver->reclaim_buffers_locked(dev, filp);
 200
 201                 drm_lock_free(dev, &dev->lock.hw_lock->lock,
 202                               _DRM_LOCKING_CONTEXT(dev->lock.hw_lock->lock));
 203
 204                 /* FIXME: may require heavy-handed reset of
 205                    hardware at this point, possibly
 206                    processed via a callback to the X
 207                    server. */
 208         } else if (dev->driver->reclaim_buffers_locked && priv->lock_count
 209                    && dev->lock.hw_lock) {
 210                 /* The lock is required to reclaim buffers */
 211                 DECLARE_WAITQUEUE(entry, current);
 212
 213                 add_wait_queue(&dev->lock.lock_queue, &entry);
 214                 for (;;) {
 215                         __set_current_state(TASK_INTERRUPTIBLE);
 216                         if (!dev->lock.hw_lock) {
 217                                 /* Device has been unregistered */
 218                                 retcode = -EINTR;
 219                                 break;
 220                         }
 221                         if (drm_lock_take(&dev->lock.hw_lock->lock,
 222                                           DRM_KERNEL_CONTEXT)) {
 223                                 dev->lock.filp = filp;
 224                                 dev->lock.lock_time = jiffies;
 225                                 atomic_inc(&dev->counts[_DRM_STAT_LOCKS]);
 226                                 break;  /* Got lock */
 227                         }
 228                         /* Contention */
 229                         schedule();
 230                         if (signal_pending(current)) {
 231                                 retcode = -ERESTARTSYS;
 232                                 break;
 233                         }
 234                 }
 235                 __set_current_state(TASK_RUNNING);
 236                 remove_wait_queue(&dev->lock.lock_queue, &entry);
 237                 if (!retcode) {
 238                         dev->driver->reclaim_buffers_locked(dev, filp);
 239                         drm_lock_free(dev, &dev->lock.hw_lock->lock,
 240                                       DRM_KERNEL_CONTEXT);
 241                 }
 242         }
 243
 244         if (drm_core_check_feature(dev, DRIVER_HAVE_DMA) &&
 245             !dev->driver->reclaim_buffers_locked) {
 246                 dev->driver->reclaim_buffers(dev, filp);
 247         }
 248
 249         drm_fasync(-1, filp, 0);
 250
 251         down(&dev->ctxlist_sem);
 252         if (dev->ctxlist && (!list_empty(&dev->ctxlist->head))) {
 253                 drm_ctx_list_t *pos, *n;
 254
 255                 list_for_each_entry_safe(pos, n, &dev->ctxlist->head, head) {
 256                         if (pos->tag == priv &&
 257                             pos->handle != DRM_KERNEL_CONTEXT) {
 258                                 if (dev->driver->context_dtor)
 259                                         dev->driver->context_dtor(dev,
 260                                                                   pos->handle);
 261
 262                                 drm_ctxbitmap_free(dev, pos->handle);
 263
 264                                 list_del(&pos->head);
 265                                 drm_free(pos, sizeof(*pos), DRM_MEM_CTXLIST);
 266                                 --dev->ctx_count;
 267                         }
 268                 }
 269         }
 270         up(&dev->ctxlist_sem);
 271
 272         down(&dev->struct_sem);
 273         if (priv->remove_auth_on_close == 1) {
 274                 drm_file_t *temp = dev->file_first;
 275                 while (temp) {
 276                         temp->authenticated = 0;
 277                         temp = temp->next;
 278                 }
 279         }
 280         if (priv->prev) {
 281                 priv->prev->next = priv->next;
 282         } else {
 283                 dev->file_first = priv->next;
 284         }
 285         if (priv->next) {
 286                 priv->next->prev = priv->prev;
 287         } else {
 288                 dev->file_last = priv->prev;
 289         }
 290         up(&dev->struct_sem);
 291
 292         if (dev->driver->postclose)
 293                 dev->driver->postclose(dev, priv);
 294
 295         drm_free(priv, sizeof(*priv), DRM_MEM_FILES);
 296
 297         /* ========================================================
 298          * End inline drm_release
 299          */
 300
 301         atomic_inc(&dev->counts[_DRM_STAT_CLOSES]);
 302         spin_lock(&dev->count_lock);
 303         if (!--dev->open_count) {
 304                 if (atomic_read(&dev->ioctl_count) || dev->blocked) {
 305                         DRM_ERROR("Device busy: %d %d\n",
 306                                   atomic_read(&dev->ioctl_count), dev->blocked);
 307                         spin_unlock(&dev->count_lock);
 308                         unlock_kernel();
 309                         return -EBUSY;
 310                 }
 311                 spin_unlock(&dev->count_lock);
 312                 unlock_kernel();
 313                 return drm_lastclose(dev);
 314         }
 315         spin_unlock(&dev->count_lock);
 316
 317         unlock_kernel();
 318
 319         return retcode;
 320 }
 321
 322 EXPORT_SYMBOL(drm_release);
 323
 324 /**
 325  * Check whether DRI will run on this CPU.
 326  *
 327  * \return non-zero if the DRI will run on this CPU, or zero otherwise.
 328  */
 329 static int drm_cpu_valid(void)
 330 {
 331 #if defined(__i386__)
 332         if (boot_cpu_data.x86 == 3)
 333                 return 0;       /* No cmpxchg on a 386 */
 334 #endif
 335 #if defined(__sparc__) && !defined(__sparc_v9__)
 336         return 0;               /* No cmpxchg before v9 sparc. */
 337 #endif
 338         return 1;
 339 }
 340
 341 /**
 342  * Called whenever a process opens /dev/drm.
 343  *
 344  * \param inode device inode.
 345  * \param filp file pointer.
 346  * \param dev device.
 347  * \return zero on success or a negative number on failure.
 348  *
 349  * Creates and initializes a drm_file structure for the file private data in \p
 350  * filp and add it into the double linked list in \p dev.
 351  */
 352 static int drm_open_helper(struct inode *inode, struct file *filp,
 353                            drm_device_t * dev)
 354 {
 355         int minor = iminor(inode);
 356         drm_file_t *priv;
 357         int ret;
 358
 359         if (filp->f_flags & O_EXCL)
 360                 return -EBUSY;  /* No exclusive opens */
 361         if (!drm_cpu_valid())
 362                 return -EINVAL;
 363
 364         DRM_DEBUG("pid = %d, minor = %d\n", current->pid, minor);
 365
 366         priv = drm_alloc(sizeof(*priv), DRM_MEM_FILES);
 367         if (!priv)
 368                 return -ENOMEM;
 369
 370         memset(priv, 0, sizeof(*priv));
 371         filp->private_data = priv;
 372         priv->uid = current->euid;
 373         priv->pid = current->pid;
 374         priv->minor = minor;
 375         priv->head = drm_heads[minor];
 376         priv->ioctl_count = 0;
 377         priv->authenticated = capable(CAP_SYS_ADMIN);
 378         priv->lock_count = 0;
 379
 380         if (dev->driver->open) {
 381                 ret = dev->driver->open(dev, priv);
 382                 if (ret < 0)
 383                         goto out_free;
 384         }
 385
 386         down(&dev->struct_sem);
 387         if (!dev->file_last) {
 388                 priv->next = NULL;
 389                 priv->prev = NULL;
 390                 dev->file_first = priv;
 391                 dev->file_last = priv;
 392         } else {
 393                 priv->next = NULL;
 394                 priv->prev = dev->file_last;
 395                 dev->file_last->next = priv;
 396                 dev->file_last = priv;
 397         }
 398         up(&dev->struct_sem);
 399
 400 #ifdef __alpha__
 401         /*
 402          * Default the hose
 403          */
 404         if (!dev->hose) {
 405                 struct pci_dev *pci_dev;
 406                 pci_dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
 407                 if (pci_dev) {
 408                         dev->hose = pci_dev->sysdata;
 409                         pci_dev_put(pci_dev);
 410                 }
 411                 if (!dev->hose) {
 412                         struct pci_bus *b = pci_bus_b(pci_root_buses.next);
 413                         if (b)
 414                                 dev->hose = b->sysdata;
 415                 }
 416         }
 417 #endif
 418
 419         return 0;
 420       out_free:
 421         drm_free(priv, sizeof(*priv), DRM_MEM_FILES);
 422         filp->private_data = NULL;
 423         return ret;
 424 }
 425
 426 /** No-op. */
 427 int drm_flush(struct file *filp)
 428 {
 429         drm_file_t *priv = filp->private_data;
 430         drm_device_t *dev = priv->head->dev;
 431
 432         DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
 433                   current->pid, (long)old_encode_dev(priv->head->device),
 434                   dev->open_count);
 435         return 0;
 436 }
 437
 438 EXPORT_SYMBOL(drm_flush);
 439
 440 /** No-op. */
 441 int drm_fasync(int fd, struct file *filp, int on)
 442 {
 443         drm_file_t *priv = filp->private_data;
 444         drm_device_t *dev = priv->head->dev;
 445         int retcode;
 446
 447         DRM_DEBUG("fd = %d, device = 0x%lx\n", fd,
 448                   (long)old_encode_dev(priv->head->device));
 449         retcode = fasync_helper(fd, filp, on, &dev->buf_async);
 450         if (retcode < 0)
 451                 return retcode;
 452         return 0;
 453 }
 454
 455 EXPORT_SYMBOL(drm_fasync);
 456
 457 /** No-op. */
 458 unsigned int drm_poll(struct file *filp, struct poll_table_struct *wait)
 459 {
 460         return 0;
 461 }
 462
 463 EXPORT_SYMBOL(drm_poll);