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 <linux/poll.h>
  39 #include <linux/smp_lock.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         int i;
  47         int ret;
  48
  49         if (dev->driver->firstopen) {
  50                 ret = dev->driver->firstopen(dev);
  51                 if (ret != 0)
  52                         return ret;
  53         }
  54
  55         atomic_set(&dev->ioctl_count, 0);
  56         atomic_set(&dev->vma_count, 0);
  57
  58         if (drm_core_check_feature(dev, DRIVER_HAVE_DMA) &&
  59             !drm_core_check_feature(dev, DRIVER_MODESET)) {
  60                 dev->buf_use = 0;
  61                 atomic_set(&dev->buf_alloc, 0);
  62
  63                 i = drm_dma_setup(dev);
  64                 if (i < 0)
  65                         return i;
  66         }
  67
  68         for (i = 0; i < ARRAY_SIZE(dev->counts); i++)
  69                 atomic_set(&dev->counts[i], 0);
  70
  71         dev->sigdata.lock = NULL;
  72
  73         dev->queue_count = 0;
  74         dev->queue_reserved = 0;
  75         dev->queue_slots = 0;
  76         dev->queuelist = NULL;
  77         dev->context_flag = 0;
  78         dev->interrupt_flag = 0;
  79         dev->dma_flag = 0;
  80         dev->last_context = 0;
  81         dev->last_switch = 0;
  82         dev->last_checked = 0;
  83         init_waitqueue_head(&dev->context_wait);
  84         dev->if_version = 0;
  85
  86         dev->ctx_start = 0;
  87         dev->lck_start = 0;
  88
  89         dev->buf_async = NULL;
  90         init_waitqueue_head(&dev->buf_readers);
  91         init_waitqueue_head(&dev->buf_writers);
  92
  93         DRM_DEBUG("\n");
  94
  95         /*
  96          * The kernel's context could be created here, but is now created
  97          * in drm_dma_enqueue.  This is more resource-efficient for
  98          * hardware that does not do DMA, but may mean that
  99          * drm_select_queue fails between the time the interrupt is
 100          * initialized and the time the queues are initialized.
 101          */
 102
 103         return 0;
 104 }
 105
 106 /**
 107  * Open file.
 108  *
 109  * \param inode device inode
 110  * \param filp file pointer.
 111  * \return zero on success or a negative number on failure.
 112  *
 113  * Searches the DRM device with the same minor number, calls open_helper(), and
 114  * increments the device open count. If the open count was previous at zero,
 115  * i.e., it's the first that the device is open, then calls setup().
 116  */
 117 int drm_open(struct inode *inode, struct file *filp)
 118 {
 119         struct drm_device *dev = NULL;
 120         int minor_id = iminor(inode);
 121         struct drm_minor *minor;
 122         int retcode = 0;
 123
 124         minor = idr_find(&drm_minors_idr, minor_id);
 125         if (!minor)
 126                 return -ENODEV;
 127
 128         if (!(dev = minor->dev))
 129                 return -ENODEV;
 130
 131         retcode = drm_open_helper(inode, filp, dev);
 132         if (!retcode) {
 133                 atomic_inc(&dev->counts[_DRM_STAT_OPENS]);
 134                 spin_lock(&dev->count_lock);
 135                 if (!dev->open_count++) {
 136                         spin_unlock(&dev->count_lock);
 137                         retcode = drm_setup(dev);
 138                         goto out;
 139                 }
 140                 spin_unlock(&dev->count_lock);
 141         }
 142 out:
 143         mutex_lock(&dev->struct_mutex);
 144         if (minor->type == DRM_MINOR_LEGACY) {
 145                 BUG_ON((dev->dev_mapping != NULL) &&
 146                         (dev->dev_mapping != inode->i_mapping));
 147                 if (dev->dev_mapping == NULL)
 148                         dev->dev_mapping = inode->i_mapping;
 149         }
 150         mutex_unlock(&dev->struct_mutex);
 151
 152         return retcode;
 153 }
 154 EXPORT_SYMBOL(drm_open);
 155
 156 /**
 157  * File \c open operation.
 158  *
 159  * \param inode device inode.
 160  * \param filp file pointer.
 161  *
 162  * Puts the dev->fops corresponding to the device minor number into
 163  * \p filp, call the \c open method, and restore the file operations.
 164  */
 165 int drm_stub_open(struct inode *inode, struct file *filp)
 166 {
 167         struct drm_device *dev = NULL;
 168         struct drm_minor *minor;
 169         int minor_id = iminor(inode);
 170         int err = -ENODEV;
 171         const struct file_operations *old_fops;
 172
 173         DRM_DEBUG("\n");
 174
 175         /* BKL pushdown: note that nothing else serializes idr_find() */
 176         lock_kernel();
 177         minor = idr_find(&drm_minors_idr, minor_id);
 178         if (!minor)
 179                 goto out;
 180
 181         if (!(dev = minor->dev))
 182                 goto out;
 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 out:
 193         unlock_kernel();
 194         return err;
 195 }
 196
 197 /**
 198  * Check whether DRI will run on this CPU.
 199  *
 200  * \return non-zero if the DRI will run on this CPU, or zero otherwise.
 201  */
 202 static int drm_cpu_valid(void)
 203 {
 204 #if defined(__i386__)
 205         if (boot_cpu_data.x86 == 3)
 206                 return 0;       /* No cmpxchg on a 386 */
 207 #endif
 208 #if defined(__sparc__) && !defined(__sparc_v9__)
 209         return 0;               /* No cmpxchg before v9 sparc. */
 210 #endif
 211         return 1;
 212 }
 213
 214 /**
 215  * Called whenever a process opens /dev/drm.
 216  *
 217  * \param inode device inode.
 218  * \param filp file pointer.
 219  * \param dev device.
 220  * \return zero on success or a negative number on failure.
 221  *
 222  * Creates and initializes a drm_file structure for the file private data in \p
 223  * filp and add it into the double linked list in \p dev.
 224  */
 225 static int drm_open_helper(struct inode *inode, struct file *filp,
 226                            struct drm_device * dev)
 227 {
 228         int minor_id = iminor(inode);
 229         struct drm_file *priv;
 230         int ret;
 231
 232         if (filp->f_flags & O_EXCL)
 233                 return -EBUSY;  /* No exclusive opens */
 234         if (!drm_cpu_valid())
 235                 return -EINVAL;
 236
 237         DRM_DEBUG("pid = %d, minor = %d\n", task_pid_nr(current), minor_id);
 238
 239         priv = drm_alloc(sizeof(*priv), DRM_MEM_FILES);
 240         if (!priv)
 241                 return -ENOMEM;
 242
 243         memset(priv, 0, sizeof(*priv));
 244         filp->private_data = priv;
 245         priv->filp = filp;
 246         priv->uid = current_euid();
 247         priv->pid = task_pid_nr(current);
 248         priv->minor = idr_find(&drm_minors_idr, minor_id);
 249         priv->ioctl_count = 0;
 250         /* for compatibility root is always authenticated */
 251         priv->authenticated = capable(CAP_SYS_ADMIN);
 252         priv->lock_count = 0;
 253
 254         INIT_LIST_HEAD(&priv->lhead);
 255         INIT_LIST_HEAD(&priv->fbs);
 256
 257         if (dev->driver->driver_features & DRIVER_GEM)
 258                 drm_gem_open(dev, priv);
 259
 260         if (dev->driver->open) {
 261                 ret = dev->driver->open(dev, priv);
 262                 if (ret < 0)
 263                         goto out_free;
 264         }
 265
 266
 267         /* if there is no current master make this fd it */
 268         mutex_lock(&dev->struct_mutex);
 269         if (!priv->minor->master) {
 270                 /* create a new master */
 271                 priv->minor->master = drm_master_create(priv->minor);
 272                 if (!priv->minor->master) {
 273                         ret = -ENOMEM;
 274                         goto out_free;
 275                 }
 276
 277                 priv->is_master = 1;
 278                 /* take another reference for the copy in the local file priv */
 279                 priv->master = drm_master_get(priv->minor->master);
 280
 281                 priv->authenticated = 1;
 282
 283                 mutex_unlock(&dev->struct_mutex);
 284                 if (dev->driver->master_create) {
 285                         ret = dev->driver->master_create(dev, priv->master);
 286                         if (ret) {
 287                                 mutex_lock(&dev->struct_mutex);
 288                                 /* drop both references if this fails */
 289                                 drm_master_put(&priv->minor->master);
 290                                 drm_master_put(&priv->master);
 291                                 mutex_unlock(&dev->struct_mutex);
 292                                 goto out_free;
 293                         }
 294                 }
 295         } else {
 296                 /* get a reference to the master */
 297                 priv->master = drm_master_get(priv->minor->master);
 298                 mutex_unlock(&dev->struct_mutex);
 299         }
 300
 301         mutex_lock(&dev->struct_mutex);
 302         list_add(&priv->lhead, &dev->filelist);
 303         mutex_unlock(&dev->struct_mutex);
 304
 305 #ifdef __alpha__
 306         /*
 307          * Default the hose
 308          */
 309         if (!dev->hose) {
 310                 struct pci_dev *pci_dev;
 311                 pci_dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
 312                 if (pci_dev) {
 313                         dev->hose = pci_dev->sysdata;
 314                         pci_dev_put(pci_dev);
 315                 }
 316                 if (!dev->hose) {
 317                         struct pci_bus *b = pci_bus_b(pci_root_buses.next);
 318                         if (b)
 319                                 dev->hose = b->sysdata;
 320                 }
 321         }
 322 #endif
 323
 324         return 0;
 325       out_free:
 326         drm_free(priv, sizeof(*priv), DRM_MEM_FILES);
 327         filp->private_data = NULL;
 328         return ret;
 329 }
 330
 331 /** No-op. */
 332 int drm_fasync(int fd, struct file *filp, int on)
 333 {
 334         struct drm_file *priv = filp->private_data;
 335         struct drm_device *dev = priv->minor->dev;
 336         int retcode;
 337
 338         DRM_DEBUG("fd = %d, device = 0x%lx\n", fd,
 339                   (long)old_encode_dev(priv->minor->device));
 340         retcode = fasync_helper(fd, filp, on, &dev->buf_async);
 341         if (retcode < 0)
 342                 return retcode;
 343         return 0;
 344 }
 345 EXPORT_SYMBOL(drm_fasync);
 346
 347 /*
 348  * Reclaim locked buffers; note that this may be a bad idea if the current
 349  * context doesn't have the hw lock...
 350  */
 351 static void drm_reclaim_locked_buffers(struct drm_device *dev, struct file *f)
 352 {
 353         struct drm_file *file_priv = f->private_data;
 354
 355         if (drm_i_have_hw_lock(dev, file_priv)) {
 356                 dev->driver->reclaim_buffers_locked(dev, file_priv);
 357         } else {
 358                 unsigned long _end = jiffies + 3 * DRM_HZ;
 359                 int locked = 0;
 360
 361                 drm_idlelock_take(&file_priv->master->lock);
 362
 363                 /*
 364                  * Wait for a while.
 365                  */
 366                 do {
 367                         spin_lock_bh(&file_priv->master->lock.spinlock);
 368                         locked = file_priv->master->lock.idle_has_lock;
 369                         spin_unlock_bh(&file_priv->master->lock.spinlock);
 370                         if (locked)
 371                                 break;
 372                         schedule();
 373                 } while (!time_after_eq(jiffies, _end));
 374
 375                 if (!locked) {
 376                         DRM_ERROR("reclaim_buffers_locked() deadlock. Please rework this\n"
 377                                   "\tdriver to use reclaim_buffers_idlelocked() instead.\n"
 378                                   "\tI will go on reclaiming the buffers anyway.\n");
 379                 }
 380
 381                 dev->driver->reclaim_buffers_locked(dev, file_priv);
 382                 drm_idlelock_release(&file_priv->master->lock);
 383         }
 384 }
 385
 386 static void drm_master_release(struct drm_device *dev, struct file *filp)
 387 {
 388         struct drm_file *file_priv = filp->private_data;
 389
 390         if (dev->driver->reclaim_buffers_locked &&
 391             file_priv->master->lock.hw_lock)
 392                 drm_reclaim_locked_buffers(dev, filp);
 393
 394         if (dev->driver->reclaim_buffers_idlelocked &&
 395             file_priv->master->lock.hw_lock) {
 396                 drm_idlelock_take(&file_priv->master->lock);
 397                 dev->driver->reclaim_buffers_idlelocked(dev, file_priv);
 398                 drm_idlelock_release(&file_priv->master->lock);
 399         }
 400
 401
 402         if (drm_i_have_hw_lock(dev, file_priv)) {
 403                 DRM_DEBUG("File %p released, freeing lock for context %d\n",
 404                           filp, _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
 405                 drm_lock_free(&file_priv->master->lock,
 406                               _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
 407         }
 408
 409         if (drm_core_check_feature(dev, DRIVER_HAVE_DMA) &&
 410             !dev->driver->reclaim_buffers_locked) {
 411                 dev->driver->reclaim_buffers(dev, file_priv);
 412         }
 413 }
 414
 415 /**
 416  * Release file.
 417  *
 418  * \param inode device inode
 419  * \param file_priv DRM file private.
 420  * \return zero on success or a negative number on failure.
 421  *
 422  * If the hardware lock is held then free it, and take it again for the kernel
 423  * context since it's necessary to reclaim buffers. Unlink the file private
 424  * data from its list and free it. Decreases the open count and if it reaches
 425  * zero calls drm_lastclose().
 426  */
 427 int drm_release(struct inode *inode, struct file *filp)
 428 {
 429         struct drm_file *file_priv = filp->private_data;
 430         struct drm_device *dev = file_priv->minor->dev;
 431         int retcode = 0;
 432
 433         lock_kernel();
 434
 435         DRM_DEBUG("open_count = %d\n", dev->open_count);
 436
 437         if (dev->driver->preclose)
 438                 dev->driver->preclose(dev, file_priv);
 439
 440         /* ========================================================
 441          * Begin inline drm_release
 442          */
 443
 444         DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
 445                   task_pid_nr(current),
 446                   (long)old_encode_dev(file_priv->minor->device),
 447                   dev->open_count);
 448
 449         /* if the master has gone away we can't do anything with the lock */
 450         if (file_priv->minor->master)
 451                 drm_master_release(dev, filp);
 452
 453         if (dev->driver->driver_features & DRIVER_GEM)
 454                 drm_gem_release(dev, file_priv);
 455
 456         mutex_lock(&dev->ctxlist_mutex);
 457         if (!list_empty(&dev->ctxlist)) {
 458                 struct drm_ctx_list *pos, *n;
 459
 460                 list_for_each_entry_safe(pos, n, &dev->ctxlist, head) {
 461                         if (pos->tag == file_priv &&
 462                             pos->handle != DRM_KERNEL_CONTEXT) {
 463                                 if (dev->driver->context_dtor)
 464                                         dev->driver->context_dtor(dev,
 465                                                                   pos->handle);
 466
 467                                 drm_ctxbitmap_free(dev, pos->handle);
 468
 469                                 list_del(&pos->head);
 470                                 drm_free(pos, sizeof(*pos), DRM_MEM_CTXLIST);
 471                                 --dev->ctx_count;
 472                         }
 473                 }
 474         }
 475         mutex_unlock(&dev->ctxlist_mutex);
 476
 477         mutex_lock(&dev->struct_mutex);
 478
 479         if (file_priv->is_master) {
 480                 struct drm_file *temp;
 481                 list_for_each_entry(temp, &dev->filelist, lhead) {
 482                         if ((temp->master == file_priv->master) &&
 483                             (temp != file_priv))
 484                                 temp->authenticated = 0;
 485                 }
 486
 487                 if (file_priv->minor->master == file_priv->master) {
 488                         /* drop the reference held my the minor */
 489                         drm_master_put(&file_priv->minor->master);
 490                 }
 491         }
 492
 493         /* drop the reference held my the file priv */
 494         drm_master_put(&file_priv->master);
 495         file_priv->is_master = 0;
 496         list_del(&file_priv->lhead);
 497         mutex_unlock(&dev->struct_mutex);
 498
 499         if (dev->driver->postclose)
 500                 dev->driver->postclose(dev, file_priv);
 501         drm_free(file_priv, sizeof(*file_priv), DRM_MEM_FILES);
 502
 503         /* ========================================================
 504          * End inline drm_release
 505          */
 506
 507         atomic_inc(&dev->counts[_DRM_STAT_CLOSES]);
 508         spin_lock(&dev->count_lock);
 509         if (!--dev->open_count) {
 510                 if (atomic_read(&dev->ioctl_count)) {
 511                         DRM_ERROR("Device busy: %d\n",
 512                                   atomic_read(&dev->ioctl_count));
 513                         spin_unlock(&dev->count_lock);
 514                         unlock_kernel();
 515                         return -EBUSY;
 516                 }
 517                 spin_unlock(&dev->count_lock);
 518                 unlock_kernel();
 519                 return drm_lastclose(dev);
 520         }
 521         spin_unlock(&dev->count_lock);
 522
 523         unlock_kernel();
 524
 525         return retcode;
 526 }
 527 EXPORT_SYMBOL(drm_release);
 528
 529 /** No-op. */
 530 unsigned int drm_poll(struct file *filp, struct poll_table_struct *wait)
 531 {
 532         return 0;
 533 }
 534 EXPORT_SYMBOL(drm_poll);