linux-core/drm_fops.c

   1 /**
   2  * \file drm_fops.h
   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_setup(drm_device_t * dev)
  41 {
  42         int i;
  43
  44         if (dev->fn_tbl->presetup)
  45                 dev->fn_tbl->presetup(dev);
  46
  47         atomic_set(&dev->ioctl_count, 0);
  48         atomic_set(&dev->vma_count, 0);
  49         dev->buf_use = 0;
  50         atomic_set(&dev->buf_alloc, 0);
  51
  52         if (drm_core_check_feature(dev, DRIVER_HAVE_DMA)) {
  53                 i = drm_dma_setup(dev);
  54                 if (i < 0)
  55                         return i;
  56         }
  57
  58         for (i = 0; i < DRM_ARRAY_SIZE(dev->counts); i++)
  59                 atomic_set(&dev->counts[i], 0);
  60
  61         for (i = 0; i < DRM_HASH_SIZE; i++) {
  62                 dev->magiclist[i].head = NULL;
  63                 dev->magiclist[i].tail = NULL;
  64         }
  65
  66         dev->ctxlist = drm_alloc(sizeof(*dev->ctxlist), DRM_MEM_CTXLIST);
  67         if (dev->ctxlist == NULL)
  68                 return -ENOMEM;
  69         memset(dev->ctxlist, 0, sizeof(*dev->ctxlist));
  70         INIT_LIST_HEAD(&dev->ctxlist->head);
  71
  72         dev->vmalist = NULL;
  73         dev->sigdata.lock = dev->lock.hw_lock = NULL;
  74         init_waitqueue_head(&dev->lock.lock_queue);
  75         dev->queue_count = 0;
  76         dev->queue_reserved = 0;
  77         dev->queue_slots = 0;
  78         dev->queuelist = NULL;
  79         dev->irq_enabled = 0;
  80         dev->context_flag = 0;
  81         dev->interrupt_flag = 0;
  82         dev->dma_flag = 0;
  83         dev->last_context = 0;
  84         dev->last_switch = 0;
  85         dev->last_checked = 0;
  86         init_waitqueue_head(&dev->context_wait);
  87         dev->if_version = 0;
  88
  89         dev->ctx_start = 0;
  90         dev->lck_start = 0;
  91
  92         dev->buf_rp = dev->buf;
  93         dev->buf_wp = dev->buf;
  94         dev->buf_end = dev->buf + DRM_BSZ;
  95         dev->buf_async = NULL;
  96         init_waitqueue_head(&dev->buf_readers);
  97         init_waitqueue_head(&dev->buf_writers);
  98
  99         DRM_DEBUG("\n");
 100
 101         /*
 102          * The kernel's context could be created here, but is now created
 103          * in drm_dma_enqueue.  This is more resource-efficient for
 104          * hardware that does not do DMA, but may mean that
 105          * drm_select_queue fails between the time the interrupt is
 106          * initialized and the time the queues are initialized.
 107          */
 108         if (dev->fn_tbl->postsetup)
 109                 dev->fn_tbl->postsetup(dev);
 110
 111         return 0;
 112 }
 113
 114 /**
 115  * Open file.
 116  *
 117  * \param inode device inode
 118  * \param filp file pointer.
 119  * \return zero on success or a negative number on failure.
 120  *
 121  * Searches the DRM device with the same minor number, calls open_helper(), and
 122  * increments the device open count. If the open count was previous at zero,
 123  * i.e., it's the first that the device is open, then calls setup().
 124  */
 125 int drm_open(struct inode *inode, struct file *filp)
 126 {
 127         drm_device_t *dev = NULL;
 128         int minor = iminor(inode);
 129         int retcode = 0;
 130
 131         if (!((minor >= 0) && (minor < cards_limit)))
 132                 return -ENODEV;
 133
 134         dev = drm_minors[minor].dev;
 135         if (!dev)
 136                 return -ENODEV;
 137
 138         retcode = drm_open_helper(inode, filp, dev);
 139         if (!retcode) {
 140                 atomic_inc(&dev->counts[_DRM_STAT_OPENS]);
 141                 spin_lock(&dev->count_lock);
 142                 if (!dev->open_count++) {
 143                         spin_unlock(&dev->count_lock);
 144                         return drm_setup(dev);
 145                 }
 146                 spin_unlock(&dev->count_lock);
 147         }
 148
 149         return retcode;
 150 }
 151 EXPORT_SYMBOL(drm_open);
 152
 153 /**
 154  * File \c open operation.
 155  *
 156  * \param inode device inode.
 157  * \param filp file pointer.
 158  *
 159  * Puts the dev->fops corresponding to the device minor number into
 160  * \p filp, call the \c open method, and restore the file operations.
 161  */
 162 int drm_stub_open(struct inode *inode, struct file *filp)
 163 {
 164         drm_device_t *dev = NULL;
 165         int minor = iminor(inode);
 166         int err = -ENODEV;
 167         struct file_operations *old_fops;
 168
 169         DRM_DEBUG("\n");
 170
 171         if (!((minor >= 0) && (minor < cards_limit)))
 172                 return -ENODEV;
 173
 174         dev = drm_minors[minor].dev;
 175         if (!dev)
 176                 return -ENODEV;
 177
 178         old_fops = filp->f_op;
 179         filp->f_op = fops_get(&dev->fn_tbl->fops);
 180         if (filp->f_op->open && (err = filp->f_op->open(inode, filp))) {
 181                 fops_put(filp->f_op);
 182                 filp->f_op = fops_get(old_fops);
 183         }
 184         fops_put(old_fops);
 185
 186         return err;
 187 }
 188
 189 /**
 190  * Called whenever a process opens /dev/drm.
 191  *
 192  * \param inode device inode.
 193  * \param filp file pointer.
 194  * \param dev device.
 195  * \return zero on success or a negative number on failure.
 196  *
 197  * Creates and initializes a drm_file structure for the file private data in \p
 198  * filp and add it into the double linked list in \p dev.
 199  */
 200 int drm_open_helper(struct inode *inode, struct file *filp, drm_device_t * dev)
 201 {
 202         int minor = iminor(inode);
 203         drm_file_t *priv;
 204         int ret;
 205
 206         if (filp->f_flags & O_EXCL)
 207                 return -EBUSY;  /* No exclusive opens */
 208         if (!drm_cpu_valid())
 209                 return -EINVAL;
 210
 211         DRM_DEBUG("pid = %d, minor = %d\n", current->pid, minor);
 212
 213         priv = drm_alloc(sizeof(*priv), DRM_MEM_FILES);
 214         if (!priv)
 215                 return -ENOMEM;
 216
 217         memset(priv, 0, sizeof(*priv));
 218         filp->private_data = priv;
 219         priv->uid = current->euid;
 220         priv->pid = current->pid;
 221         priv->minor = minor;
 222         priv->dev = dev;
 223         priv->ioctl_count = 0;
 224         priv->authenticated = capable(CAP_SYS_ADMIN);
 225         priv->lock_count = 0;
 226
 227         if (dev->fn_tbl->open_helper) {
 228                 ret = dev->fn_tbl->open_helper(dev, priv);
 229                 if (ret < 0)
 230                         goto out_free;
 231         }
 232
 233         down(&dev->struct_sem);
 234         if (!dev->file_last) {
 235                 priv->next = NULL;
 236                 priv->prev = NULL;
 237                 dev->file_first = priv;
 238                 dev->file_last = priv;
 239         } else {
 240                 priv->next = NULL;
 241                 priv->prev = dev->file_last;
 242                 dev->file_last->next = priv;
 243                 dev->file_last = priv;
 244         }
 245         up(&dev->struct_sem);
 246
 247 #ifdef __alpha__
 248         /*
 249          * Default the hose
 250          */
 251         if (!dev->hose) {
 252                 struct pci_dev *pci_dev;
 253                 pci_dev = pci_find_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
 254                 if (pci_dev)
 255                         dev->hose = pci_dev->sysdata;
 256                 if (!dev->hose) {
 257                         struct pci_bus *b = pci_bus_b(pci_root_buses.next);
 258                         if (b)
 259                                 dev->hose = b->sysdata;
 260                 }
 261         }
 262 #endif
 263
 264         return 0;
 265       out_free:
 266         drm_free(priv, sizeof(*priv), DRM_MEM_FILES);
 267         filp->private_data = NULL;
 268         return ret;
 269 }
 270
 271 /** No-op. */
 272 int drm_fasync(int fd, struct file *filp, int on)
 273 {
 274         drm_file_t *priv = filp->private_data;
 275         drm_device_t *dev = priv->dev;
 276         int retcode;
 277
 278         DRM_DEBUG("fd = %d, device = 0x%lx\n", fd,
 279                   (long)old_encode_dev(dev->device));
 280         retcode = fasync_helper(fd, filp, on, &dev->buf_async);
 281         if (retcode < 0)
 282                 return retcode;
 283         return 0;
 284 }
 285 EXPORT_SYMBOL(drm_fasync);
 286
 287 /**
 288  * Release file.
 289  *
 290  * \param inode device inode
 291  * \param filp file pointer.
 292  * \return zero on success or a negative number on failure.
 293  *
 294  * If the hardware lock is held then free it, and take it again for the kernel
 295  * context since it's necessary to reclaim buffers. Unlink the file private
 296  * data from its list and free it. Decreases the open count and if it reaches
 297  * zero calls takedown().
 298  */
 299 int drm_release(struct inode *inode, struct file *filp)
 300 {
 301         drm_file_t *priv = filp->private_data;
 302         drm_device_t *dev;
 303         int retcode = 0;
 304
 305         lock_kernel();
 306         dev = priv->dev;
 307
 308         DRM_DEBUG("open_count = %d\n", dev->open_count);
 309
 310         if (dev->fn_tbl->prerelease)
 311                 dev->fn_tbl->prerelease(dev, filp);
 312
 313         /* ========================================================
 314          * Begin inline drm_release
 315          */
 316
 317         DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
 318                   current->pid, (long)old_encode_dev(dev->device),
 319                   dev->open_count);
 320
 321         if (priv->lock_count && dev->lock.hw_lock &&
 322             _DRM_LOCK_IS_HELD(dev->lock.hw_lock->lock) &&
 323             dev->lock.filp == filp) {
 324                 DRM_DEBUG("File %p released, freeing lock for context %d\n",
 325                           filp, _DRM_LOCKING_CONTEXT(dev->lock.hw_lock->lock));
 326
 327                 if (dev->fn_tbl->release)
 328                         dev->fn_tbl->release(dev, filp);
 329
 330                 drm_lock_free(dev, &dev->lock.hw_lock->lock,
 331                               _DRM_LOCKING_CONTEXT(dev->lock.hw_lock->lock));
 332
 333                 /* FIXME: may require heavy-handed reset of
 334                    hardware at this point, possibly
 335                    processed via a callback to the X
 336                    server. */
 337         } else if (dev->fn_tbl->release && priv->lock_count
 338                    && dev->lock.hw_lock) {
 339                 /* The lock is required to reclaim buffers */
 340                 DECLARE_WAITQUEUE(entry, current);
 341
 342                 add_wait_queue(&dev->lock.lock_queue, &entry);
 343                 for (;;) {
 344                         current->state = TASK_INTERRUPTIBLE;
 345                         if (!dev->lock.hw_lock) {
 346                                 /* Device has been unregistered */
 347                                 retcode = -EINTR;
 348                                 break;
 349                         }
 350                         if (drm_lock_take(&dev->lock.hw_lock->lock,
 351                                           DRM_KERNEL_CONTEXT)) {
 352                                 dev->lock.filp = filp;
 353                                 dev->lock.lock_time = jiffies;
 354                                 atomic_inc(&dev->counts[_DRM_STAT_LOCKS]);
 355                                 break;  /* Got lock */
 356                         }
 357                         /* Contention */
 358                         schedule();
 359                         if (signal_pending(current)) {
 360                                 retcode = -ERESTARTSYS;
 361                                 break;
 362                         }
 363                 }
 364                 current->state = TASK_RUNNING;
 365                 remove_wait_queue(&dev->lock.lock_queue, &entry);
 366                 if (!retcode) {
 367                         if (dev->fn_tbl->release)
 368                                 dev->fn_tbl->release(dev, filp);
 369                         drm_lock_free(dev, &dev->lock.hw_lock->lock,
 370                                       DRM_KERNEL_CONTEXT);
 371                 }
 372         }
 373
 374         if (drm_core_check_feature(dev, DRIVER_HAVE_DMA)) {
 375                 dev->fn_tbl->reclaim_buffers(filp);
 376         }
 377
 378         drm_fasync(-1, filp, 0);
 379
 380         down(&dev->ctxlist_sem);
 381         if (!list_empty(&dev->ctxlist->head)) {
 382                 drm_ctx_list_t *pos, *n;
 383
 384                 list_for_each_entry_safe(pos, n, &dev->ctxlist->head, head) {
 385                         if (pos->tag == priv &&
 386                             pos->handle != DRM_KERNEL_CONTEXT) {
 387                                 if (dev->fn_tbl->context_dtor)
 388                                         dev->fn_tbl->context_dtor(dev,
 389                                                                   pos->handle);
 390
 391                                 drm_ctxbitmap_free(dev, pos->handle);
 392
 393                                 list_del(&pos->head);
 394                                 drm_free(pos, sizeof(*pos), DRM_MEM_CTXLIST);
 395                                 --dev->ctx_count;
 396                         }
 397                 }
 398         }
 399         up(&dev->ctxlist_sem);
 400
 401         down(&dev->struct_sem);
 402         if (priv->remove_auth_on_close == 1) {
 403                 drm_file_t *temp = dev->file_first;
 404                 while (temp) {
 405                         temp->authenticated = 0;
 406                         temp = temp->next;
 407                 }
 408         }
 409         if (priv->prev) {
 410                 priv->prev->next = priv->next;
 411         } else {
 412                 dev->file_first = priv->next;
 413         }
 414         if (priv->next) {
 415                 priv->next->prev = priv->prev;
 416         } else {
 417                 dev->file_last = priv->prev;
 418         }
 419         up(&dev->struct_sem);
 420
 421         if (dev->fn_tbl->free_filp_priv)
 422                 dev->fn_tbl->free_filp_priv(dev, priv);
 423         drm_free(priv, sizeof(*priv), DRM_MEM_FILES);
 424
 425         /* ========================================================
 426          * End inline drm_release
 427          */
 428
 429         atomic_inc(&dev->counts[_DRM_STAT_CLOSES]);
 430         spin_lock(&dev->count_lock);
 431         if (!--dev->open_count) {
 432                 if (atomic_read(&dev->ioctl_count) || dev->blocked) {
 433                         DRM_ERROR("Device busy: %d %d\n",
 434                                   atomic_read(&dev->ioctl_count), dev->blocked);
 435                         spin_unlock(&dev->count_lock);
 436                         unlock_kernel();
 437                         return -EBUSY;
 438                 }
 439                 spin_unlock(&dev->count_lock);
 440                 unlock_kernel();
 441                 return drm_takedown(dev);
 442         }
 443         spin_unlock(&dev->count_lock);
 444
 445         unlock_kernel();
 446
 447         return retcode;
 448 }
 449 EXPORT_SYMBOL(drm_release);