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                            struct drm_device * dev);
  43
  44 static int drm_setup(struct drm_device * 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         dev->sigdata.lock = NULL;
  83         init_waitqueue_head(&dev->lock.lock_queue);
  84         dev->queue_count = 0;
  85         dev->queue_reserved = 0;
  86         dev->queue_slots = 0;
  87         dev->queuelist = NULL;
  88         dev->irq_enabled = 0;
  89         dev->context_flag = 0;
  90         dev->interrupt_flag = 0;
  91         dev->dma_flag = 0;
  92         dev->last_context = 0;
  93         dev->last_switch = 0;
  94         dev->last_checked = 0;
  95         init_waitqueue_head(&dev->context_wait);
  96         dev->if_version = 0;
  97
  98         dev->ctx_start = 0;
  99         dev->lck_start = 0;
 100
 101         dev->buf_async = NULL;
 102         init_waitqueue_head(&dev->buf_readers);
 103         init_waitqueue_head(&dev->buf_writers);
 104
 105         DRM_DEBUG("\n");
 106
 107         /*
 108          * The kernel's context could be created here, but is now created
 109          * in drm_dma_enqueue.  This is more resource-efficient for
 110          * hardware that does not do DMA, but may mean that
 111          * drm_select_queue fails between the time the interrupt is
 112          * initialized and the time the queues are initialized.
 113          */
 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         struct drm_device *dev = NULL;
 132         int minor_id = iminor(inode);
 133         struct drm_minor *minor;
 134         int retcode = 0;
 135
 136         minor = idr_find(&drm_minors_idr, minor_id);
 137         if (!minor)
 138                 return -ENODEV;
 139
 140         if (!(dev = minor->dev))
 141                 return -ENODEV;
 142
 143         retcode = drm_open_helper(inode, filp, dev);
 144         if (!retcode) {
 145                 atomic_inc(&dev->counts[_DRM_STAT_OPENS]);
 146                 spin_lock(&dev->count_lock);
 147                 if (!dev->open_count++) {
 148                         spin_unlock(&dev->count_lock);
 149                         return drm_setup(dev);
 150                 }
 151                 spin_unlock(&dev->count_lock);
 152         }
 153
 154         return retcode;
 155 }
 156 EXPORT_SYMBOL(drm_open);
 157
 158 /**
 159  * File \c open operation.
 160  *
 161  * \param inode device inode.
 162  * \param filp file pointer.
 163  *
 164  * Puts the dev->fops corresponding to the device minor number into
 165  * \p filp, call the \c open method, and restore the file operations.
 166  */
 167 int drm_stub_open(struct inode *inode, struct file *filp)
 168 {
 169         struct drm_device *dev = NULL;
 170         struct drm_minor *minor;
 171         int minor_id = iminor(inode);
 172         int err = -ENODEV;
 173         const struct file_operations *old_fops;
 174
 175         DRM_DEBUG("\n");
 176
 177         minor = idr_find(&drm_minors_idr, minor_id);
 178         if (!minor)
 179                 return -ENODEV;
 180
 181         if (!(dev = minor->dev))
 182                 return -ENODEV;
 183
 184         old_fops = filp->f_op;
 185         filp->f_op = fops_get(&dev->driver->fops);
 186         if (filp->f_op->open && (err = filp->f_op->open(inode, filp))) {
 187                 fops_put(filp->f_op);
 188                 filp->f_op = fops_get(old_fops);
 189         }
 190         fops_put(old_fops);
 191
 192         return err;
 193 }
 194
 195 /**
 196  * Check whether DRI will run on this CPU.
 197  *
 198  * \return non-zero if the DRI will run on this CPU, or zero otherwise.
 199  */
 200 static int drm_cpu_valid(void)
 201 {
 202 #if defined(__i386__)
 203         if (boot_cpu_data.x86 == 3)
 204                 return 0;       /* No cmpxchg on a 386 */
 205 #endif
 206 #if defined(__sparc__) && !defined(__sparc_v9__)
 207         return 0;               /* No cmpxchg before v9 sparc. */
 208 #endif
 209         return 1;
 210 }
 211
 212 /**
 213  * Called whenever a process opens /dev/drm.
 214  *
 215  * \param inode device inode.
 216  * \param filp file pointer.
 217  * \param dev device.
 218  * \return zero on success or a negative number on failure.
 219  *
 220  * Creates and initializes a drm_file structure for the file private data in \p
 221  * filp and add it into the double linked list in \p dev.
 222  */
 223 static int drm_open_helper(struct inode *inode, struct file *filp,
 224                            struct drm_device * dev)
 225 {
 226         int minor_id = iminor(inode);
 227         struct drm_file *priv;
 228         int ret;
 229
 230         if (filp->f_flags & O_EXCL)
 231                 return -EBUSY;  /* No exclusive opens */
 232         if (!drm_cpu_valid())
 233                 return -EINVAL;
 234
 235         DRM_DEBUG("pid = %d, minor = %d\n", task_pid_nr(current), minor_id);
 236
 237         priv = drm_alloc(sizeof(*priv), DRM_MEM_FILES);
 238         if (!priv)
 239                 return -ENOMEM;
 240
 241         memset(priv, 0, sizeof(*priv));
 242         filp->private_data = priv;
 243         priv->filp = filp;
 244         priv->uid = current->euid;
 245         priv->pid = task_pid_nr(current);
 246         priv->minor = idr_find(&drm_minors_idr, minor_id);
 247         priv->ioctl_count = 0;
 248         /* for compatibility root is always authenticated */
 249         priv->authenticated = capable(CAP_SYS_ADMIN);
 250         priv->lock_count = 0;
 251
 252         INIT_LIST_HEAD(&priv->lhead);
 253
 254         if (dev->driver->open) {
 255                 ret = dev->driver->open(dev, priv);
 256                 if (ret < 0)
 257                         goto out_free;
 258         }
 259
 260         mutex_lock(&dev->struct_mutex);
 261         if (list_empty(&dev->filelist))
 262                 priv->master = 1;
 263
 264         list_add(&priv->lhead, &dev->filelist);
 265         mutex_unlock(&dev->struct_mutex);
 266
 267 #ifdef __alpha__
 268         /*
 269          * Default the hose
 270          */
 271         if (!dev->hose) {
 272                 struct pci_dev *pci_dev;
 273                 pci_dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
 274                 if (pci_dev) {
 275                         dev->hose = pci_dev->sysdata;
 276                         pci_dev_put(pci_dev);
 277                 }
 278                 if (!dev->hose) {
 279                         struct pci_bus *b = pci_bus_b(pci_root_buses.next);
 280                         if (b)
 281                                 dev->hose = b->sysdata;
 282                 }
 283         }
 284 #endif
 285
 286         return 0;
 287       out_free:
 288         drm_free(priv, sizeof(*priv), DRM_MEM_FILES);
 289         filp->private_data = NULL;
 290         return ret;
 291 }
 292
 293 /** No-op. */
 294 int drm_fasync(int fd, struct file *filp, int on)
 295 {
 296         struct drm_file *priv = filp->private_data;
 297         struct drm_device *dev = priv->minor->dev;
 298         int retcode;
 299
 300         DRM_DEBUG("fd = %d, device = 0x%lx\n", fd,
 301                   (long)old_encode_dev(priv->minor->device));
 302         retcode = fasync_helper(fd, filp, on, &dev->buf_async);
 303         if (retcode < 0)
 304                 return retcode;
 305         return 0;
 306 }
 307 EXPORT_SYMBOL(drm_fasync);
 308
 309 /**
 310  * Release file.
 311  *
 312  * \param inode device inode
 313  * \param file_priv DRM file private.
 314  * \return zero on success or a negative number on failure.
 315  *
 316  * If the hardware lock is held then free it, and take it again for the kernel
 317  * context since it's necessary to reclaim buffers. Unlink the file private
 318  * data from its list and free it. Decreases the open count and if it reaches
 319  * zero calls drm_lastclose().
 320  */
 321 int drm_release(struct inode *inode, struct file *filp)
 322 {
 323         struct drm_file *file_priv = filp->private_data;
 324         struct drm_device *dev = file_priv->minor->dev;
 325         int retcode = 0;
 326
 327         lock_kernel();
 328
 329         DRM_DEBUG("open_count = %d\n", dev->open_count);
 330
 331         if (dev->driver->preclose)
 332                 dev->driver->preclose(dev, file_priv);
 333
 334         /* ========================================================
 335          * Begin inline drm_release
 336          */
 337
 338         DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
 339                   task_pid_nr(current),
 340                   (long)old_encode_dev(file_priv->minor->device),
 341                   dev->open_count);
 342
 343         if (dev->driver->reclaim_buffers_locked && dev->lock.hw_lock) {
 344                 if (drm_i_have_hw_lock(dev, file_priv)) {
 345                         dev->driver->reclaim_buffers_locked(dev, file_priv);
 346                 } else {
 347                         unsigned long endtime = jiffies + 3 * DRM_HZ;
 348                         int locked = 0;
 349
 350                         drm_idlelock_take(&dev->lock);
 351
 352                         /*
 353                          * Wait for a while.
 354                          */
 355
 356                         do{
 357                                 spin_lock_bh(&dev->lock.spinlock);
 358                                 locked = dev->lock.idle_has_lock;
 359                                 spin_unlock_bh(&dev->lock.spinlock);
 360                                 if (locked)
 361                                         break;
 362                                 schedule();
 363                         } while (!time_after_eq(jiffies, endtime));
 364
 365                         if (!locked) {
 366                                 DRM_ERROR("reclaim_buffers_locked() deadlock. Please rework this\n"
 367                                           "\tdriver to use reclaim_buffers_idlelocked() instead.\n"
 368                                           "\tI will go on reclaiming the buffers anyway.\n");
 369                         }
 370
 371                         dev->driver->reclaim_buffers_locked(dev, file_priv);
 372                         drm_idlelock_release(&dev->lock);
 373                 }
 374         }
 375
 376         if (dev->driver->reclaim_buffers_idlelocked && dev->lock.hw_lock) {
 377
 378                 drm_idlelock_take(&dev->lock);
 379                 dev->driver->reclaim_buffers_idlelocked(dev, file_priv);
 380                 drm_idlelock_release(&dev->lock);
 381
 382         }
 383
 384         if (drm_i_have_hw_lock(dev, file_priv)) {
 385                 DRM_DEBUG("File %p released, freeing lock for context %d\n",
 386                           filp, _DRM_LOCKING_CONTEXT(dev->lock.hw_lock->lock));
 387
 388                 drm_lock_free(&dev->lock,
 389                               _DRM_LOCKING_CONTEXT(dev->lock.hw_lock->lock));
 390         }
 391
 392
 393         if (drm_core_check_feature(dev, DRIVER_HAVE_DMA) &&
 394             !dev->driver->reclaim_buffers_locked) {
 395                 dev->driver->reclaim_buffers(dev, file_priv);
 396         }
 397
 398         drm_fasync(-1, filp, 0);
 399
 400         mutex_lock(&dev->ctxlist_mutex);
 401         if (!list_empty(&dev->ctxlist)) {
 402                 struct drm_ctx_list *pos, *n;
 403
 404                 list_for_each_entry_safe(pos, n, &dev->ctxlist, head) {
 405                         if (pos->tag == file_priv &&
 406                             pos->handle != DRM_KERNEL_CONTEXT) {
 407                                 if (dev->driver->context_dtor)
 408                                         dev->driver->context_dtor(dev,
 409                                                                   pos->handle);
 410
 411                                 drm_ctxbitmap_free(dev, pos->handle);
 412
 413                                 list_del(&pos->head);
 414                                 drm_free(pos, sizeof(*pos), DRM_MEM_CTXLIST);
 415                                 --dev->ctx_count;
 416                         }
 417                 }
 418         }
 419         mutex_unlock(&dev->ctxlist_mutex);
 420
 421         mutex_lock(&dev->struct_mutex);
 422         if (file_priv->remove_auth_on_close == 1) {
 423                 struct drm_file *temp;
 424
 425                 list_for_each_entry(temp, &dev->filelist, lhead)
 426                         temp->authenticated = 0;
 427         }
 428         list_del(&file_priv->lhead);
 429         mutex_unlock(&dev->struct_mutex);
 430
 431         if (dev->driver->postclose)
 432                 dev->driver->postclose(dev, file_priv);
 433         drm_free(file_priv, sizeof(*file_priv), DRM_MEM_FILES);
 434
 435         /* ========================================================
 436          * End inline drm_release
 437          */
 438
 439         atomic_inc(&dev->counts[_DRM_STAT_CLOSES]);
 440         spin_lock(&dev->count_lock);
 441         if (!--dev->open_count) {
 442                 if (atomic_read(&dev->ioctl_count) || dev->blocked) {
 443                         DRM_ERROR("Device busy: %d %d\n",
 444                                   atomic_read(&dev->ioctl_count), dev->blocked);
 445                         spin_unlock(&dev->count_lock);
 446                         unlock_kernel();
 447                         return -EBUSY;
 448                 }
 449                 spin_unlock(&dev->count_lock);
 450                 unlock_kernel();
 451                 return drm_lastclose(dev);
 452         }
 453         spin_unlock(&dev->count_lock);
 454
 455         unlock_kernel();
 456
 457         return retcode;
 458 }
 459 EXPORT_SYMBOL(drm_release);
 460
 461 /** No-op. */
 462 unsigned int drm_poll(struct file *filp, struct poll_table_struct *wait)
 463 {
 464         return 0;
 465 }
 466 EXPORT_SYMBOL(drm_poll);