drivers/gpu/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 #include <linux/smp_lock.h>
  41
  42 static int drm_open_helper(struct inode *inode, struct file *filp,
  43                            struct drm_device * dev);
  44
  45 static int drm_setup(struct drm_device * dev)
  46 {
  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         atomic_set(&dev->ioctl_count, 0);
  57         atomic_set(&dev->vma_count, 0);
  58         dev->buf_use = 0;
  59         atomic_set(&dev->buf_alloc, 0);
  60
  61         if (drm_core_check_feature(dev, DRIVER_HAVE_DMA)) {
  62                 i = drm_dma_setup(dev);
  63                 if (i < 0)
  64                         return i;
  65         }
  66
  67         for (i = 0; i < ARRAY_SIZE(dev->counts); i++)
  68                 atomic_set(&dev->counts[i], 0);
  69
  70         dev->sigdata.lock = NULL;
  71
  72         dev->queue_count = 0;
  73         dev->queue_reserved = 0;
  74         dev->queue_slots = 0;
  75         dev->queuelist = NULL;
  76         dev->context_flag = 0;
  77         dev->interrupt_flag = 0;
  78         dev->dma_flag = 0;
  79         dev->last_context = 0;
  80         dev->last_switch = 0;
  81         dev->last_checked = 0;
  82         init_waitqueue_head(&dev->context_wait);
  83         dev->if_version = 0;
  84
  85         dev->ctx_start = 0;
  86         dev->lck_start = 0;
  87
  88         dev->buf_async = NULL;
  89         init_waitqueue_head(&dev->buf_readers);
  90         init_waitqueue_head(&dev->buf_writers);
  91
  92         DRM_DEBUG("\n");
  93
  94         /*
  95          * The kernel's context could be created here, but is now created
  96          * in drm_dma_enqueue.  This is more resource-efficient for
  97          * hardware that does not do DMA, but may mean that
  98          * drm_select_queue fails between the time the interrupt is
  99          * initialized and the time the queues are initialized.
 100          */
 101
 102         return 0;
 103 }
 104
 105 /**
 106  * Open file.
 107  *
 108  * \param inode device inode
 109  * \param filp file pointer.
 110  * \return zero on success or a negative number on failure.
 111  *
 112  * Searches the DRM device with the same minor number, calls open_helper(), and
 113  * increments the device open count. If the open count was previous at zero,
 114  * i.e., it's the first that the device is open, then calls setup().
 115  */
 116 int drm_open(struct inode *inode, struct file *filp)
 117 {
 118         struct drm_device *dev = NULL;
 119         int minor_id = iminor(inode);
 120         struct drm_minor *minor;
 121         int retcode = 0;
 122
 123         minor = idr_find(&drm_minors_idr, minor_id);
 124         if (!minor)
 125                 return -ENODEV;
 126
 127         if (!(dev = minor->dev))
 128                 return -ENODEV;
 129
 130         retcode = drm_open_helper(inode, filp, dev);
 131         if (!retcode) {
 132                 atomic_inc(&dev->counts[_DRM_STAT_OPENS]);
 133                 spin_lock(&dev->count_lock);
 134                 if (!dev->open_count++) {
 135                         spin_unlock(&dev->count_lock);
 136                         return drm_setup(dev);
 137                 }
 138                 spin_unlock(&dev->count_lock);
 139         }
 140
 141         return retcode;
 142 }
 143 EXPORT_SYMBOL(drm_open);
 144
 145 /**
 146  * File \c open operation.
 147  *
 148  * \param inode device inode.
 149  * \param filp file pointer.
 150  *
 151  * Puts the dev->fops corresponding to the device minor number into
 152  * \p filp, call the \c open method, and restore the file operations.
 153  */
 154 int drm_stub_open(struct inode *inode, struct file *filp)
 155 {
 156         struct drm_device *dev = NULL;
 157         struct drm_minor *minor;
 158         int minor_id = iminor(inode);
 159         int err = -ENODEV;
 160         const struct file_operations *old_fops;
 161
 162         DRM_DEBUG("\n");
 163
 164         /* BKL pushdown: note that nothing else serializes idr_find() */
 165         lock_kernel();
 166         minor = idr_find(&drm_minors_idr, minor_id);
 167         if (!minor)
 168                 goto out;
 169
 170         if (!(dev = minor->dev))
 171                 goto out;
 172
 173         old_fops = filp->f_op;
 174         filp->f_op = fops_get(&dev->driver->fops);
 175         if (filp->f_op->open && (err = filp->f_op->open(inode, filp))) {
 176                 fops_put(filp->f_op);
 177                 filp->f_op = fops_get(old_fops);
 178         }
 179         fops_put(old_fops);
 180
 181 out:
 182         unlock_kernel();
 183         return err;
 184 }
 185
 186 /**
 187  * Check whether DRI will run on this CPU.
 188  *
 189  * \return non-zero if the DRI will run on this CPU, or zero otherwise.
 190  */
 191 static int drm_cpu_valid(void)
 192 {
 193 #if defined(__i386__)
 194         if (boot_cpu_data.x86 == 3)
 195                 return 0;       /* No cmpxchg on a 386 */
 196 #endif
 197 #if defined(__sparc__) && !defined(__sparc_v9__)
 198         return 0;               /* No cmpxchg before v9 sparc. */
 199 #endif
 200         return 1;
 201 }
 202
 203 /**
 204  * Called whenever a process opens /dev/drm.
 205  *
 206  * \param inode device inode.
 207  * \param filp file pointer.
 208  * \param dev device.
 209  * \return zero on success or a negative number on failure.
 210  *
 211  * Creates and initializes a drm_file structure for the file private data in \p
 212  * filp and add it into the double linked list in \p dev.
 213  */
 214 static int drm_open_helper(struct inode *inode, struct file *filp,
 215                            struct drm_device * dev)
 216 {
 217         int minor_id = iminor(inode);
 218         struct drm_file *priv;
 219         int ret;
 220
 221         if (filp->f_flags & O_EXCL)
 222                 return -EBUSY;  /* No exclusive opens */
 223         if (!drm_cpu_valid())
 224                 return -EINVAL;
 225
 226         DRM_DEBUG("pid = %d, minor = %d\n", task_pid_nr(current), minor_id);
 227
 228         priv = drm_alloc(sizeof(*priv), DRM_MEM_FILES);
 229         if (!priv)
 230                 return -ENOMEM;
 231
 232         memset(priv, 0, sizeof(*priv));
 233         filp->private_data = priv;
 234         priv->filp = filp;
 235         priv->uid = current_euid();
 236         priv->pid = task_pid_nr(current);
 237         priv->minor = idr_find(&drm_minors_idr, minor_id);
 238         priv->ioctl_count = 0;
 239         /* for compatibility root is always authenticated */
 240         priv->authenticated = capable(CAP_SYS_ADMIN);
 241         priv->lock_count = 0;
 242
 243         INIT_LIST_HEAD(&priv->lhead);
 244
 245         if (dev->driver->driver_features & DRIVER_GEM)
 246                 drm_gem_open(dev, priv);
 247
 248         if (dev->driver->open) {
 249                 ret = dev->driver->open(dev, priv);
 250                 if (ret < 0)
 251                         goto out_free;
 252         }
 253
 254
 255         /* if there is no current master make this fd it */
 256         mutex_lock(&dev->struct_mutex);
 257         if (!priv->minor->master) {
 258                 /* create a new master */
 259                 priv->minor->master = drm_master_create(priv->minor);
 260                 if (!priv->minor->master) {
 261                         ret = -ENOMEM;
 262                         goto out_free;
 263                 }
 264
 265                 priv->is_master = 1;
 266                 /* take another reference for the copy in the local file priv */
 267                 priv->master = drm_master_get(priv->minor->master);
 268
 269                 priv->authenticated = 1;
 270
 271                 mutex_unlock(&dev->struct_mutex);
 272                 if (dev->driver->master_create) {
 273                         ret = dev->driver->master_create(dev, priv->master);
 274                         if (ret) {
 275                                 mutex_lock(&dev->struct_mutex);
 276                                 /* drop both references if this fails */
 277                                 drm_master_put(&priv->minor->master);
 278                                 drm_master_put(&priv->master);
 279                                 mutex_unlock(&dev->struct_mutex);
 280                                 goto out_free;
 281                         }
 282                 }
 283         } else {
 284                 /* get a reference to the master */
 285                 priv->master = drm_master_get(priv->minor->master);
 286                 mutex_unlock(&dev->struct_mutex);
 287         }
 288
 289         mutex_lock(&dev->struct_mutex);
 290         list_add(&priv->lhead, &dev->filelist);
 291         mutex_unlock(&dev->struct_mutex);
 292
 293 #ifdef __alpha__
 294         /*
 295          * Default the hose
 296          */
 297         if (!dev->hose) {
 298                 struct pci_dev *pci_dev;
 299                 pci_dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
 300                 if (pci_dev) {
 301                         dev->hose = pci_dev->sysdata;
 302                         pci_dev_put(pci_dev);
 303                 }
 304                 if (!dev->hose) {
 305                         struct pci_bus *b = pci_bus_b(pci_root_buses.next);
 306                         if (b)
 307                                 dev->hose = b->sysdata;
 308                 }
 309         }
 310 #endif
 311
 312         return 0;
 313       out_free:
 314         drm_free(priv, sizeof(*priv), DRM_MEM_FILES);
 315         filp->private_data = NULL;
 316         return ret;
 317 }
 318
 319 /** No-op. */
 320 int drm_fasync(int fd, struct file *filp, int on)
 321 {
 322         struct drm_file *priv = filp->private_data;
 323         struct drm_device *dev = priv->minor->dev;
 324         int retcode;
 325
 326         DRM_DEBUG("fd = %d, device = 0x%lx\n", fd,
 327                   (long)old_encode_dev(priv->minor->device));
 328         retcode = fasync_helper(fd, filp, on, &dev->buf_async);
 329         if (retcode < 0)
 330                 return retcode;
 331         return 0;
 332 }
 333 EXPORT_SYMBOL(drm_fasync);
 334
 335 /*
 336  * Reclaim locked buffers; note that this may be a bad idea if the current
 337  * context doesn't have the hw lock...
 338  */
 339 static void drm_reclaim_locked_buffers(struct drm_device *dev, struct file *f)
 340 {
 341         struct drm_file *file_priv = f->private_data;
 342
 343         if (drm_i_have_hw_lock(dev, file_priv)) {
 344                 dev->driver->reclaim_buffers_locked(dev, file_priv);
 345         } else {
 346                 unsigned long _end = jiffies + 3 * DRM_HZ;
 347                 int locked = 0;
 348
 349                 drm_idlelock_take(&file_priv->master->lock);
 350
 351                 /*
 352                  * Wait for a while.
 353                  */
 354                 do {
 355                         spin_lock_bh(&file_priv->master->lock.spinlock);
 356                         locked = file_priv->master->lock.idle_has_lock;
 357                         spin_unlock_bh(&file_priv->master->lock.spinlock);
 358                         if (locked)
 359                                 break;
 360                         schedule();
 361                 } while (!time_after_eq(jiffies, _end));
 362
 363                 if (!locked) {
 364                         DRM_ERROR("reclaim_buffers_locked() deadlock. Please rework this\n"
 365                                   "\tdriver to use reclaim_buffers_idlelocked() instead.\n"
 366                                   "\tI will go on reclaiming the buffers anyway.\n");
 367                 }
 368
 369                 dev->driver->reclaim_buffers_locked(dev, file_priv);
 370                 drm_idlelock_release(&file_priv->master->lock);
 371         }
 372 }
 373
 374 static void drm_master_release(struct drm_device *dev, struct file *filp)
 375 {
 376         struct drm_file *file_priv = filp->private_data;
 377
 378         if (dev->driver->reclaim_buffers_locked &&
 379             file_priv->master->lock.hw_lock)
 380                 drm_reclaim_locked_buffers(dev, filp);
 381
 382         if (dev->driver->reclaim_buffers_idlelocked &&
 383             file_priv->master->lock.hw_lock) {
 384                 drm_idlelock_take(&file_priv->master->lock);
 385                 dev->driver->reclaim_buffers_idlelocked(dev, file_priv);
 386                 drm_idlelock_release(&file_priv->master->lock);
 387         }
 388
 389
 390         if (drm_i_have_hw_lock(dev, file_priv)) {
 391                 DRM_DEBUG("File %p released, freeing lock for context %d\n",
 392                           filp, _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
 393                 drm_lock_free(&file_priv->master->lock,
 394                               _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
 395         }
 396
 397         if (drm_core_check_feature(dev, DRIVER_HAVE_DMA) &&
 398             !dev->driver->reclaim_buffers_locked) {
 399                 dev->driver->reclaim_buffers(dev, file_priv);
 400         }
 401 }
 402
 403 /**
 404  * Release file.
 405  *
 406  * \param inode device inode
 407  * \param file_priv DRM file private.
 408  * \return zero on success or a negative number on failure.
 409  *
 410  * If the hardware lock is held then free it, and take it again for the kernel
 411  * context since it's necessary to reclaim buffers. Unlink the file private
 412  * data from its list and free it. Decreases the open count and if it reaches
 413  * zero calls drm_lastclose().
 414  */
 415 int drm_release(struct inode *inode, struct file *filp)
 416 {
 417         struct drm_file *file_priv = filp->private_data;
 418         struct drm_device *dev = file_priv->minor->dev;
 419         int retcode = 0;
 420
 421         lock_kernel();
 422
 423         DRM_DEBUG("open_count = %d\n", dev->open_count);
 424
 425         if (dev->driver->preclose)
 426                 dev->driver->preclose(dev, file_priv);
 427
 428         /* ========================================================
 429          * Begin inline drm_release
 430          */
 431
 432         DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
 433                   task_pid_nr(current),
 434                   (long)old_encode_dev(file_priv->minor->device),
 435                   dev->open_count);
 436
 437         /* if the master has gone away we can't do anything with the lock */
 438         if (file_priv->minor->master)
 439                 drm_master_release(dev, filp);
 440
 441         if (dev->driver->driver_features & DRIVER_GEM)
 442                 drm_gem_release(dev, file_priv);
 443
 444         mutex_lock(&dev->ctxlist_mutex);
 445         if (!list_empty(&dev->ctxlist)) {
 446                 struct drm_ctx_list *pos, *n;
 447
 448                 list_for_each_entry_safe(pos, n, &dev->ctxlist, head) {
 449                         if (pos->tag == file_priv &&
 450                             pos->handle != DRM_KERNEL_CONTEXT) {
 451                                 if (dev->driver->context_dtor)
 452                                         dev->driver->context_dtor(dev,
 453                                                                   pos->handle);
 454
 455                                 drm_ctxbitmap_free(dev, pos->handle);
 456
 457                                 list_del(&pos->head);
 458                                 drm_free(pos, sizeof(*pos), DRM_MEM_CTXLIST);
 459                                 --dev->ctx_count;
 460                         }
 461                 }
 462         }
 463         mutex_unlock(&dev->ctxlist_mutex);
 464
 465         mutex_lock(&dev->struct_mutex);
 466
 467         if (file_priv->is_master) {
 468                 struct drm_file *temp;
 469                 list_for_each_entry(temp, &dev->filelist, lhead) {
 470                         if ((temp->master == file_priv->master) &&
 471                             (temp != file_priv))
 472                                 temp->authenticated = 0;
 473                 }
 474
 475                 if (file_priv->minor->master == file_priv->master) {
 476                         /* drop the reference held my the minor */
 477                         drm_master_put(&file_priv->minor->master);
 478                 }
 479         }
 480
 481         /* drop the reference held my the file priv */
 482         drm_master_put(&file_priv->master);
 483         file_priv->is_master = 0;
 484         list_del(&file_priv->lhead);
 485         mutex_unlock(&dev->struct_mutex);
 486
 487         if (dev->driver->postclose)
 488                 dev->driver->postclose(dev, file_priv);
 489         drm_free(file_priv, sizeof(*file_priv), DRM_MEM_FILES);
 490
 491         /* ========================================================
 492          * End inline drm_release
 493          */
 494
 495         atomic_inc(&dev->counts[_DRM_STAT_CLOSES]);
 496         spin_lock(&dev->count_lock);
 497         if (!--dev->open_count) {
 498                 if (atomic_read(&dev->ioctl_count)) {
 499                         DRM_ERROR("Device busy: %d\n",
 500                                   atomic_read(&dev->ioctl_count));
 501                         spin_unlock(&dev->count_lock);
 502                         unlock_kernel();
 503                         return -EBUSY;
 504                 }
 505                 spin_unlock(&dev->count_lock);
 506                 unlock_kernel();
 507                 return drm_lastclose(dev);
 508         }
 509         spin_unlock(&dev->count_lock);
 510
 511         unlock_kernel();
 512
 513         return retcode;
 514 }
 515 EXPORT_SYMBOL(drm_release);
 516
 517 /** No-op. */
 518 unsigned int drm_poll(struct file *filp, struct poll_table_struct *wait)
 519 {
 520         return 0;
 521 }
 522 EXPORT_SYMBOL(drm_poll);