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         u32 sareapage;
  50
  51         if (dev->driver->firstopen) {
  52                 ret = dev->driver->firstopen(dev);
  53                 if (ret != 0)
  54                         return ret;
  55         }
  56
  57         dev->magicfree.next = NULL;
  58
  59         /* prebuild the SAREA */
  60         sareapage = max_t(unsigned, SAREA_MAX, PAGE_SIZE);
  61         i = drm_addmap(dev, 0, sareapage, _DRM_SHM, _DRM_CONTAINS_LOCK, &map);
  62         if (i != 0)
  63                 return i;
  64
  65         atomic_set(&dev->ioctl_count, 0);
  66         atomic_set(&dev->vma_count, 0);
  67         dev->buf_use = 0;
  68         atomic_set(&dev->buf_alloc, 0);
  69
  70         if (drm_core_check_feature(dev, DRIVER_HAVE_DMA)) {
  71                 i = drm_dma_setup(dev);
  72                 if (i < 0)
  73                         return i;
  74         }
  75
  76         for (i = 0; i < ARRAY_SIZE(dev->counts); i++)
  77                 atomic_set(&dev->counts[i], 0);
  78
  79         drm_ht_create(&dev->magiclist, DRM_MAGIC_HASH_ORDER);
  80         INIT_LIST_HEAD(&dev->magicfree);
  81
  82         INIT_LIST_HEAD(&dev->ctxlist);
  83         INIT_LIST_HEAD(&dev->vmalist);
  84
  85         dev->sigdata.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         INIT_LIST_HEAD(&priv->lhead);
 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 (list_empty(&dev->filelist))
 267                 priv->master = 1;
 268
 269         list_add(&priv->lhead, &dev->filelist);
 270         mutex_unlock(&dev->struct_mutex);
 271
 272 #ifdef __alpha__
 273         /*
 274          * Default the hose
 275          */
 276         if (!dev->hose) {
 277                 struct pci_dev *pci_dev;
 278                 pci_dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
 279                 if (pci_dev) {
 280                         dev->hose = pci_dev->sysdata;
 281                         pci_dev_put(pci_dev);
 282                 }
 283                 if (!dev->hose) {
 284                         struct pci_bus *b = pci_bus_b(pci_root_buses.next);
 285                         if (b)
 286                                 dev->hose = b->sysdata;
 287                 }
 288         }
 289 #endif
 290
 291         return 0;
 292       out_free:
 293         drm_free(priv, sizeof(*priv), DRM_MEM_FILES);
 294         filp->private_data = NULL;
 295         return ret;
 296 }
 297
 298 /** No-op. */
 299 int drm_fasync(int fd, struct file *filp, int on)
 300 {
 301         drm_file_t *priv = filp->private_data;
 302         drm_device_t *dev = priv->head->dev;
 303         int retcode;
 304
 305         DRM_DEBUG("fd = %d, device = 0x%lx\n", fd,
 306                   (long)old_encode_dev(priv->head->device));
 307         retcode = fasync_helper(fd, filp, on, &dev->buf_async);
 308         if (retcode < 0)
 309                 return retcode;
 310         return 0;
 311 }
 312 EXPORT_SYMBOL(drm_fasync);
 313
 314 /**
 315  * Release file.
 316  *
 317  * \param inode device inode
 318  * \param filp file pointer.
 319  * \return zero on success or a negative number on failure.
 320  *
 321  * If the hardware lock is held then free it, and take it again for the kernel
 322  * context since it's necessary to reclaim buffers. Unlink the file private
 323  * data from its list and free it. Decreases the open count and if it reaches
 324  * zero calls drm_lastclose().
 325  */
 326 int drm_release(struct inode *inode, struct file *filp)
 327 {
 328         drm_file_t *priv = filp->private_data;
 329         drm_device_t *dev;
 330         int retcode = 0;
 331
 332         lock_kernel();
 333         dev = priv->head->dev;
 334
 335         DRM_DEBUG("open_count = %d\n", dev->open_count);
 336
 337         if (dev->driver->preclose)
 338                 dev->driver->preclose(dev, filp);
 339
 340         /* ========================================================
 341          * Begin inline drm_release
 342          */
 343
 344         DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
 345                   current->pid, (long)old_encode_dev(priv->head->device),
 346                   dev->open_count);
 347
 348         if (dev->driver->reclaim_buffers_locked && dev->lock.hw_lock) {
 349                 if (drm_i_have_hw_lock(filp)) {
 350                         dev->driver->reclaim_buffers_locked(dev, filp);
 351                 } else {
 352                         unsigned long _end=jiffies + 3*DRM_HZ;
 353                         int locked = 0;
 354
 355                         drm_idlelock_take(&dev->lock);
 356
 357                         /*
 358                          * Wait for a while.
 359                          */
 360
 361                         do{
 362                                 spin_lock(&dev->lock.spinlock);
 363                                 locked = dev->lock.idle_has_lock;
 364                                 spin_unlock(&dev->lock.spinlock);
 365                                 if (locked)
 366                                         break;
 367                                 schedule();
 368                         } while (!time_after_eq(jiffies, _end));
 369
 370                         if (!locked) {
 371                                 DRM_ERROR("reclaim_buffers_locked() deadlock. Please rework this\n"
 372                                           "\tdriver to use reclaim_buffers_idlelocked() instead.\n"
 373                                           "\tI will go on reclaiming the buffers anyway.\n");
 374                         }
 375
 376                         dev->driver->reclaim_buffers_locked(dev, filp);
 377                         drm_idlelock_release(&dev->lock);
 378                 }
 379         }
 380
 381         if (dev->driver->reclaim_buffers_idlelocked && dev->lock.hw_lock) {
 382
 383                 drm_idlelock_take(&dev->lock);
 384                 dev->driver->reclaim_buffers_idlelocked(dev, filp);
 385                 drm_idlelock_release(&dev->lock);
 386
 387         }
 388
 389         if (drm_i_have_hw_lock(filp)) {
 390                 DRM_DEBUG("File %p released, freeing lock for context %d\n",
 391                           filp, _DRM_LOCKING_CONTEXT(dev->lock.hw_lock->lock));
 392
 393                 drm_lock_free(&dev->lock,
 394                               _DRM_LOCKING_CONTEXT(dev->lock.hw_lock->lock));
 395         }
 396
 397
 398         if (drm_core_check_feature(dev, DRIVER_HAVE_DMA) &&
 399             !dev->driver->reclaim_buffers_locked) {
 400                 dev->driver->reclaim_buffers(dev, filp);
 401         }
 402
 403         drm_fasync(-1, filp, 0);
 404
 405         mutex_lock(&dev->ctxlist_mutex);
 406         if (!list_empty(&dev->ctxlist)) {
 407                 drm_ctx_list_t *pos, *n;
 408
 409                 list_for_each_entry_safe(pos, n, &dev->ctxlist, head) {
 410                         if (pos->tag == priv &&
 411                             pos->handle != DRM_KERNEL_CONTEXT) {
 412                                 if (dev->driver->context_dtor)
 413                                         dev->driver->context_dtor(dev,
 414                                                                   pos->handle);
 415
 416                                 drm_ctxbitmap_free(dev, pos->handle);
 417
 418                                 list_del(&pos->head);
 419                                 drm_free(pos, sizeof(*pos), DRM_MEM_CTXLIST);
 420                                 --dev->ctx_count;
 421                         }
 422                 }
 423         }
 424         mutex_unlock(&dev->ctxlist_mutex);
 425
 426         mutex_lock(&dev->struct_mutex);
 427         if (priv->remove_auth_on_close == 1) {
 428                 drm_file_t *temp;
 429
 430                 list_for_each_entry(temp, &dev->filelist, lhead)
 431                         temp->authenticated = 0;
 432         }
 433         list_del(&priv->lhead);
 434         mutex_unlock(&dev->struct_mutex);
 435
 436         if (dev->driver->postclose)
 437                 dev->driver->postclose(dev, priv);
 438         drm_free(priv, sizeof(*priv), DRM_MEM_FILES);
 439
 440         /* ========================================================
 441          * End inline drm_release
 442          */
 443
 444         atomic_inc(&dev->counts[_DRM_STAT_CLOSES]);
 445         spin_lock(&dev->count_lock);
 446         if (!--dev->open_count) {
 447                 if (atomic_read(&dev->ioctl_count) || dev->blocked) {
 448                         DRM_ERROR("Device busy: %d %d\n",
 449                                   atomic_read(&dev->ioctl_count), dev->blocked);
 450                         spin_unlock(&dev->count_lock);
 451                         unlock_kernel();
 452                         return -EBUSY;
 453                 }
 454                 spin_unlock(&dev->count_lock);
 455                 unlock_kernel();
 456                 return drm_lastclose(dev);
 457         }
 458         spin_unlock(&dev->count_lock);
 459
 460         unlock_kernel();
 461
 462         return retcode;
 463 }
 464 EXPORT_SYMBOL(drm_release);
 465
 466 /** No-op. */
 467 unsigned int drm_poll(struct file *filp, struct poll_table_struct *wait)
 468 {
 469         return 0;
 470 }
 471 EXPORT_SYMBOL(drm_poll);